scholarly journals Bacterial Oxidation of Arsenite II. The Activity of Washed Suspensions

1954 ◽  
Vol 7 (4) ◽  
pp. 479 ◽  
Author(s):  
AW Turner ◽  
JW Legge
Keyword(s):  
Synthetic Medium ◽  
Bacterial Oxidation ◽  
In Cells

Maximum arsenite-oxidizing activity of a pseudomonad (Ps. arsenoxydansquinque) isolated from "oxidized" arsenical cattle-dipping fluids was found in cells 3-4 days old, when cultivated in a synthetic medium containing arsenite. The system is adaptive, cells cultivated in the absence of arsenite showing no arsenite-oxidizing activity.

scholarly journals PHAGE FORMATION IN STAPHYLOCOCCUS MUSCAE CULTURES

1949 ◽  
Vol 32 (3) ◽  
pp. 301-311 ◽  
Author(s):  
Winston H. Price
Keyword(s):  
Active Substance ◽  
Synthetic Medium ◽  
Calf Thymus ◽  
Enzyme Formation ◽  
In Cells

1. A non-dialyzable fraction from fresh bakers' yeast stimulates the formation of S. muscae virus in cells in synthetic medium in the log phase of multiplication. 2. A similar fraction was not found in calf thymus, pancreas, or liver. 3. The active substance in this fraction has been partially purified. 4. This substance is taken up by the cells. In the absence of virus the added substance is metabolized to a form no longer available for virus formation. 5. A purified yeast fraction, which stimulates adaptive enzyme formation in yeast, has been found to stimulate virus formation in the S. muscae system. 6. The similarities between the yeast fraction that stimulates adaptive enzyme formation and the yeast fraction that stimulates virus formation are discussed.

scholarly journals PHAGE FORMATION IN STAPHYLOCOCCUS MUSCAE CULTURES

1949 ◽  
Vol 32 (4) ◽  
pp. 481-488
Author(s):  
Winston H. Price
Keyword(s):  
Virus Particle ◽  
Synthetic Medium ◽  
Multiple Infection ◽  
Virus Release ◽  
Cellular Lysis ◽  
In Cells

1. In the synthetic medium of Fildes contaming hydrolyzed casein virus release is not correlated with observable cellular lysis under conditions of a very low multiple infection. 2. In cells with a high multiple infection, lysis occurs much sooner than in cells with a low multiple infection and virus release is correlated with cellular lysis. The experiments indicate that it is the virus particle itself which accelerates lysis under these conditions. 3. A non-dialyzable fraction has been isolated from yeast, the addition of which results in cellular lysis occurring at a sooner than usual interval and being correlated with virus release in cells having a very low multiple infection. 4. By varying the concentration of the yeast fraction, it is possible to lyse the cells at varying times under conditions of a low multiple infection.

Stimulierung von Kulturen embryonaler Rattenzellen durch Kälberserum / Stimulation of Embryonic Rat Cells in Culture by Calf Serum

1972 ◽  
Vol 27 (5) ◽  
pp. 562-566 ◽  
Author(s):  
Johanna Grimm ◽  
Werner Frank
Keyword(s):  
Synthetic Medium ◽  
Calf Serum ◽  
Lag Phase ◽  
Double Labelling ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free ◽  
Protein Binding Assay ◽  
Adenosine Phosphates ◽  
In Cells

Embryonic rat cells cultured in a synthetic medium are stopped in G1 phase if serum is omitted from the culture medium. On addition of calf serum these cells resume DNA synthesis after a lag phase of 15—20 hours. In the present paper the events concerning the metabolism of adenosine phosphates after stimulation by serum have been examined. The results are the following:1. The concentration of cAMP in cells which have been incubated for 24 hours in serum-free medium is 32 times higher than that in cells growing in medium containing 10 per cent calf serum; the accumulated cAMP is metabolized within 10 min after the addition of 10 per cent calf serum. This has been confirmed by a double labelling technique after preincubation with radioactive adenosine as well as by estimation of cAMP using a protein-binding assay.2. A cAMP-specific phosphodiesterase is activated shortly after stimulation; the enzyme activity in dialysed cell homogenates is increased within 30 min by a factor of 2.3. Cells incubated in serum-free and those in serum-containing medium have equal amounts of ATP. On addition of serum the ATP concentration in cells preincubated in serum-free medium decreases by 27%; the original level is restored 20—30 min later.

Heterogeneity of Size and Distribution of Intramembrane Particles in the Plasma Membrane of Yeast

1977 ◽  
Vol 35 ◽  
pp. 596-597
Author(s):  
E. Keyhani
Keyword(s):  
Plasma Membrane ◽  
Candida Utilis ◽  
Synthetic Medium ◽  
Freeze Fracture ◽  
Translational Diffusion ◽  
Yeast Cells ◽  
Distilled Water ◽  
Intramembrane Particles ◽  
The Matrix ◽  
Water Cell

The matrix of biological membranes consists of a lipid bilayer into which proteins or protein aggregates are intercalated. Freeze-fracture techni- ques permit these proteins, perhaps in association with lipids, to be visualized in the hydrophobic regions of the membrane. Thus, numerous intramembrane particles (IMP) have been found on the fracture faces of membranes from a wide variety of cells (1-3). A recognized property of IMP is their tendency to form aggregates in response to changes in experi- mental conditions (4,5), perhaps as a result of translational diffusion through the viscous plane of the membrane. The purpose of this communica- tion is to describe the distribution and size of IMP in the plasma membrane of yeast (Candida utilis).Yeast cells (ATCC 8205) were grown in synthetic medium (6), and then harvested after 16 hours of culture, and washed twice in distilled water. Cell pellets were suspended in growth medium supplemented with 30% glycerol and incubated for 30 minutes at 0°C, centrifuged, and prepared for freeze-fracture, as described earlier (2,3).

Cytoplasmic Tubules in Cells Infected with Laryngotracheitis Virus

1969 ◽  
Vol 27 ◽  
pp. 376-377
Author(s):  
A. M. Watrach
Keyword(s):  
Tissue Culture ◽  
Small Proportion ◽  
Chicken Embryo ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
Morphologic Characteristics ◽  
Infectious Laryngotracheitis ◽  
Laryngotracheitis Virus ◽  
In Cells

During a study of the development of infectious laryngotracheitis (LT) virus in tissue culture cells, unusual tubular formations were found in the cytoplasm of a small proportion of the affected cells. It is the purpose of this report to describe the morphologic characteristics of the tubules and to discuss their possible association with the development of virus.The source and maintenance of the strain of LT virus have been described. Prior to this study, the virus was passed several times in chicken embryo kidney (CEK) tissue culture cells.

Effect of Some Metabolic Inhibitors on Vinblastine-Induced Ribosomal-Granular Material Complexes

1971 ◽  
Vol 29 ◽  
pp. 548-549
Author(s):  
Awtar Krishan ◽  
Dora Hsu
Keyword(s):  
Granular Material ◽  
Rna Synthesis ◽  
Culture Medium ◽  
Actinomycin D ◽  
Metabolic Inhibitors ◽  
Protein And Rna Synthesis ◽  
Apparent Reduction ◽  
Plant Alkaloids ◽  
In Cells

Cells exposed to antitumor plant alkaloids, vinblastine and vincristine sulfate have large proteinacious crystals and complexes of ribosomes, helical polyribosomes and electron-dense granular material (ribosomal complexes) in their cytoplasm, Binding of H3-colchicine by the in vivo crystals shows that they contain microtubular proteins. Association of ribosomal complexes with the crystals suggests that these structures may be interrelated.In the present study cultured human leukemic lymphoblasts (CCRF-CEM), were incubated with protein and RNA-synthesis inhibitors, p. fluorophenylalanine, puromycin, cycloheximide or actinomycin-D before the addition of crystal-inducing doses of vinblastine to the culture medium. None of these compounds could completely prevent the formation of the ribosomal complexes or the crystals. However, in cells pre-incubated with puromycin, cycloheximide, or actinomycin-D, a reduction in the number and size of the ribosomal complexes was seen. Large helical polyribosomes were absent in the ribosomal complexes of cells treated with puromycin, while in cells exposed to cycloheximide, there was an apparent reduction in the number of ribosomes associated with the ribosomal complexes (Fig. 2).

Detection of Nucleic Acids in Cells or Tissue Sections Using In situ Polymerase Chain Reaction (PCR)

1996 ◽  
Vol 54 ◽  
pp. 16-17
Author(s):  
J. R. Hully ◽  
K. R. Luehrsen ◽  
K. Aoyagi ◽  
C. Shoemaker ◽  
R. Abramson
Keyword(s):  
Nucleic Acids ◽  
Viral Infections ◽  
Anatomical Location ◽  
Rt Pcr ◽  
Reverse Transcription Pcr ◽  
Cellular Source ◽  
Gene Transcripts ◽  
Initial Description ◽  
In Cells

The development of PCR technology has greatly accelerated medical research at the genetic and molecular levels. Until recently, the inherent sensitivity of this technique has been limited to isolated preparations of nucleic acids which lack or at best have limited morphological information. With the obvious exception of cell lines, traditional PCR or reverse transcription-PCR (RT-PCR) cannot identify the cellular source of the amplified product. In contrast, in situ hybridization (ISH) by definition, defines the anatomical location of a gene and/or it’s product. However, this technique lacks the sensitivity of PCR and cannot routinely detect less than 10 to 20 copies per cell. Consequently, the localization of rare transcripts, latent viral infections, foreign or altered genes cannot be identified by this technique. In situ PCR or in situ RT-PCR is a combination of the two techniques, exploiting the sensitivity of PCR and the anatomical definition provided by ISH. Since it’s initial description considerable advances have been made in the application of in situ PCR, improvements in protocols, and the development of hardware dedicated to in situ PCR using conventional microscope slides. Our understanding of the importance of viral latency or viral burden in regards to HIV, HPV, and KSHV infections has benefited from this technique, enabling detection of single viral copies in cells or tissue otherwise thought to be normal. Clearly, this technique will be useful tool in pathobiology especially carcinogenesis, gene therapy and manipulations, the study of rare gene transcripts, and forensics.

Absence of temporal ordering of apoptotic features in heat-shock treated leukemia and lymphoma cell lines

1996 ◽  
Vol 54 ◽  
pp. 758-759
Author(s):  
D. W. Fairbain ◽  
M.D. Standing ◽  
K.L. O'Neill
Keyword(s):  
Heat Shock ◽  
Cell Lines ◽  
Chromatin Condensation ◽  
Membrane Integrity ◽  
Resistant Cell ◽  
Membrane Blebbing ◽  
Late Loss ◽  
Induced Apoptosis ◽  
Dying Cells ◽  
In Cells

Apoptosis is a genetically defined response to physiological stimuli that results in cellular suicide. Features common to apoptotic cells include chromatin condensation, oligonucleosomal DNA fragmentation, membrane blebbing, nuclear destruction, and late loss of ability to exclude vital dyes. These characteristics contrast markedly from pathological necrosis, in which membrane integrity loss is demonstrated early, and other features of apoptosis, which allow a non-inflammatory removal of dead and dying cells, are absent. Using heat shock-induced apoptosis as a model for examining stress response in cells, we undertook to categorize a variety of human leukemias and lymphomas with regard to their response to heat shock. We were also interested in determining whether a common temporal order was followed in cells dying by apoptosis. In addition, based on our previous results, we investigated whether increasing heat load resulted in increased apoptosis, with particular interest in relatively resistant cell lines, or whether the mode of death changed from apoptosis to necrosis.

Umatilla Virus Association with Fibrils and Tubules in Cultured Cells

1980 ◽  
Vol 38 ◽  
pp. 476-477
Author(s):  
Neil M. Foster ◽  
Ruth D. Breckon
Keyword(s):  
Bluetongue Virus ◽  
Linear Array ◽  
Cultured Cells ◽  
Intimate Association ◽  
Infected Cells ◽  
Dark Staining ◽  
In Cells

Macrotubules have been described1 in cells infected with Umatilla virus (UMAV), an orbivirus for which bluetongue virus (BTV) is the protype. Macrotubules, often in linear array, were observed in the cytoplasm and in intimate association with viroplasms of infected cells. Macrotubules had outside and inside diameters of 20 and 15 nm and many had dark-staining centers with diameters similar to the interiors of the tubules. UMAV was 60 nm and the RNA core was 30 nm in diameter. This report describes the association of UMAV with macrotubules and two types of microtubules.

Photo-tethered molecular beacons for superior light-induction

2021 ◽  
Author(s):  
Robin Klimek ◽  
Mantian Wang ◽  
Vivien R. McKenney ◽  
Erin M. Schuman ◽  
Alexander Heckel
Keyword(s):  
Molecular Beacons ◽  
Light Induction ◽  
In Cells

Photolabile circularization of molecular beacons via backbone phosphates leads to superior probes to study spatiotemporal aspects of RNA in cells.

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