scholarly journals Salmonella stimulate macrophage macropinocytosis and persist within spacious phagosomes.

1994 ◽  
Vol 179 (2) ◽  
pp. 601-608 ◽  
Author(s):  
C M Alpuche-Aranda ◽  
E L Racoosin ◽  
J A Swanson ◽  
S I Miller
Keyword(s):  
Bone Marrow ◽  
Plasma Membrane ◽  
Time Lapse ◽  
Membrane Ruffling ◽  
Mouse Macrophages ◽  
Constitutive Mutation ◽  
Microscopic Studies ◽  
Specific Igg ◽  
Salmonella Survival ◽  
Time Lapse Video

Light microscopic studies of phagocytosis showed that Salmonella typhimurium entered mouse macrophages enclosed in spacious phagosomes (SP). Viewed by time-lapse video microscopy, bone marrow-derived macrophages exposed to S. typhimurium displayed generalized plasma membrane ruffling and macropinocytosis. Phagosomes containing Salmonella were morphologically indistinguishable from macropinosomes. SP formation was observed after several methods of bacterial opsonization, although bacteria opsonized with specific IgG appeared initially in small phagosomes that later enlarged. In contrast to macropinosomes induced by growth factors, which shrink completely within 15 min, SP persisted in the cytoplasm, enlarging often by fusion with macropinosomes or other SP. A Salmonella strain containing a constitutive mutation in the phoP virulence regulatory locus (PhoPc) induced significantly fewer SP. Similar to Yersinia enterocolitica, PhoPc bacteria entered macrophages in close-fitting phagosomes, consistent with that expected for conventional receptor-mediated phagocytosis. These results suggest that formation of SP contributes to Salmonella survival and virulence.

Visualization of Membrane Sorting and Fusion in Living Cells using Total Internal Reflection (TIR) and Multicolor Video Microscopy

2001 ◽  
Vol 7 (S2) ◽  
pp. 34-35
Author(s):  
Derek Toomre ◽  
Patrick Keller ◽  
Elena Diaz ◽  
Jamie White ◽  
Kai Simons
Keyword(s):  
Plasma Membrane ◽  
Total Internal Reflection ◽  
Fluorescent Protein ◽  
Time Lapse ◽  
Living Cells ◽  
Video Microscopy ◽  
Internal Reflection ◽  
Fast Time ◽  
Cellular Polarity ◽  
Microscopy Technique

Post-Golgi sorting of different classes of newly synthesized proteins and lipids is central to the generation and maintenance of cellular polarity. to directly visualize the dynamics and location of apical/basolateral sorting and trafficking we used fast time-lapse multicolor video microscopy in living cells. Specifically, green fluorescent protein color variants (cyan, CFP; yellow, YFP) of apical cargo (GPI-anchored) and basolateral cargo (vesicular stomatitis virus glycoprotein, VSVG) were generated; see FIG 1. Fast dual color fluorescence video microscopy allowed visualization with high temporal and spatial resolution. Our studies revealed that apical and basolateral cargo progressively segregated into large domains in Golgi/TGN structures, excluded resident proteins, and exited in separate transport containers. These carries remained distinct and did not merge with endocytic structures en route to the plasma membrane. Interestingly, our data suggest that the primary sorting occurs by lateral segregation in the Golgi, prior to budding (FIG 2). Further characterization of morphological differences of apical versus basolateral transport carriers was achieved using a specialized microscopy technique called total internal reflection (TIR) microscopy. with this approach only the bottom of the cell (<100 nm) was illuminated by an exponentially decaying evanescent “wave” of light. A series of images, taken at ∼1 second intervals, shows a bright “flash” of fluorescence when the vesicle fuse with the plasma membrane and the fluorophore diffuses into the plasma membrane (FIG 3).

Motion of Active Fluids: Diffusion Dynamics of Cyanobacteria

2016 ◽  
Author(s):  
Thomas Vourc’h ◽  
Julien Léopoldès ◽  
Annick Méjean ◽  
Hassan Peerhossaini
Keyword(s):  
Time Lapse ◽  
Global Behavior ◽  
Diffusion Dynamics ◽  
Mean Squared Displacement ◽  
Terrestrial Environments ◽  
The Mean ◽  
Micro Organisms ◽  
Synechocystis Sp ◽  
Time Lapse Video ◽  
Pcc 6803

Cyanobacteria are photosynthetic micro-organisms colonizing all aquatic and terrestrial environments. The motility of such living micro-organisms should make their diffusion distinct from typical Brownian motion. This diffusion can be investigated in terms of global behavior (Fickian or not) and in terms of displacement probabilities, which provide more detail about the motility process. Using cyanobacterium Synechocystis sp. PCC 6803 as the model micro-organism, we carry out time-lapse video microscopy to track and analyze the bacteria’s trajectories, from which we compute the mean-squared displacement (MSD) and the distribution function of displacement probabilities. We find that the motility of Synechocystis sp. PCC 6803 is intermittent: high-motility “run” phases are separated by low-motility “tumble” phases corresponding to trapped states. However, this intermittent motility leads to a Fickian diffusive behavior, as shown by the evolution of the MSD with time.

scholarly journals CELL SURFACE IMMUNOGLOBULIN

1972 ◽  
Vol 135 (6) ◽  
pp. 1392-1405 ◽  
Author(s):  
Charles J. Sherr ◽  
Sonia Baur ◽  
Inge Grundke ◽  
Joseph Zeligs ◽  
Barbara Zeligs ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Plasma Membrane ◽  
Cell Surface ◽  
Noncovalent Interactions ◽  
Subcellular Fractionation ◽  
Splenic Lymphocytes ◽  
Surface Immunoglobulin ◽  
Established Line ◽  
Intracellular Proteins ◽  
Daudi Cells

Cells from an established line of Burkitt lymphoma (Daudi) were enzymatically radioiodinated, and labeled Ig from the cell surface was isolated and studied. Subcellular fractionation of labeled cells confirmed that intracellular proteins from the cytoplasm are not iodinated by this method. Radioactive Ig was identified as monomeric (8S) IgM, and an average of 105 Ig molecules was found per cell. Ig molecules could be released from the plasma membrane by detergent lysis under nonreducing conditions indicating that attachment of Ig to the plasma membrane occurs via noncovalent interactions. The ratio of µ/L radioactivity in surface Ig was the same as that of total cellular Ig radioiodinated in solution suggesting that a large portion of the Fc fragment is not buried within the membrane. In contrast to the results obtained with cell surface Ig, most intracellular Ig was found as "free" µ- and L chains regardless of whether lysates were labeled with 125I or cells were labeled with leucine-3H. The results indicate that only a small percentage of the total Ig of Daudi cells is associated with the cell surface and suggest that covalent assembly of Ig occurs at or near the time that the molecule becomes part of the plasma membrane. Similarities between cell surface Ig on normal splenic lymphocytes and Daudi cells suggest that the latter is a neoplasm of bone marrow-derived lymphocytes.

scholarly journals Time-lapse 3D Imaging of Phagocytosis by Mouse Macrophages

10.3791/57566 ◽  
2018 ◽  
Author(s):  
Markus Horsthemke ◽  
Janine Wilden ◽  
Anne C. Bachg ◽  
Peter J. Hanley
Keyword(s):  
3D Imaging ◽  
Time Lapse ◽  
Mouse Macrophages

scholarly journals A Neonate with Down’s Syndrome and Transient Abnormal Myelopoiesis: Serial Blood and Bone Marrow Studies

Blood ◽  
1970 ◽  
Vol 36 (4) ◽  
pp. 443-447 ◽  
Author(s):  
TAKESHI NAGAO ◽  
BEATRICE C. LAMPKIN ◽  
GEORGE HUG
Keyword(s):  
Bone Marrow ◽  
Marrow Cell ◽  
Down's Syndrome ◽  
Down’S Syndrome ◽  
Male Infant ◽  
First Year ◽  
Electron Microscopic ◽  
Transient Abnormal Myelopoiesis ◽  
Microscopic Studies ◽  
First Year Of Life

Abstract Observations were made of the blood and bone marrow of a male infant with Down’s syndrome during the first year of life. At 4 days of age there were 36,500 myeloblasts/cu.mm. in the blood and 10.8 per cent myeloblasts in the marrow. Initially it appeared the patient had acute myeloblastic leukemia. However, the clinical course and kinetic and electron microscopic studies of his bone marrow cell population indicate he did not have acute leukemia.

Collecting Vehicle-Speed Data by Using Time-Lapse Video Recording Equipment

2003 ◽  
Vol 1855 (1) ◽  
pp. 97-104 ◽  
Author(s):  
Christopher Strong ◽  
Scott Lowry ◽  
Peter McCarthy
Keyword(s):  
Real Time ◽  
Video Recording ◽  
Warning System ◽  
Time Lapse ◽  
Vehicle Speed ◽  
Recording Equipment ◽  
Safety Improvement ◽  
Camera Location ◽  
Message Signs ◽  
Time Lapse Video

An innovative application of time-lapse video recording is used to assist in an evaluation of a highway safety improvement. The improvement is an icy-curve warning system near Fredonyer Summit in northern California that activates real-time motorist warnings via extinguishable message signs, based on weather readings collected from road weather information systems. A measure of effectiveness is whether motorist speed is reduced as a result of real-time warnings to drivers. Why indirect speed measurement with video was preferred over radar for this case is discussed, as is how specific methodological issues related to the custom-built equipment, including camera location and orientation, distance benchmarking, and data collection and reduction. Theoretical and empirical accuracy measurements show that the video surveillance trailers yield results comparable to radar and, hence, would be applicable for studies in which speed change is measured. Because this particular technology had not been used previously, several lessons are documented that may help determine where and how similar equipment may be optimally used in future studies.

scholarly journals MORPHOLOGY AND PEROXIDASE CYTOCHEMISTRY OF MOUSE PROMONOCYTES, MONOCYTES, AND MACROPHAGES

1970 ◽  
Vol 132 (4) ◽  
pp. 794-812 ◽  
Author(s):  
Ralph van Furth ◽  
James G. Hirsch ◽  
Martha E. Fedorko
Keyword(s):  
Bone Marrow Cells ◽  
Peritoneal Macrophages ◽  
Blood Monocytes ◽  
Peripheral Blood Monocytes ◽  
Membrane Ruffling ◽  
Mouse Macrophages ◽  
Granular Cytoplasm ◽  
Monocytes And Macrophages ◽  
Mature Mouse ◽  
Peroxidase Cytochemistry

Mouse promonocytes have been identified and studied in cultures of bone marrow cells. These cells have a diameter of 14–20 µ, and in stained preparations reveal a large, indented or folded nucleus, and basophilic, finely granular cytoplasm. The living promonocyte viewed by phase contrast shows additional features: nucleoli, small dense bodies, and vesicles in the cytoplasm adjacent to the nuclear hilus, and slight membrane ruffling. Prominent ultrastructural components of promonocytes include a well developed Golgi apparatus, small numbers of centrosomal granules and vacuoles, extensive ribosomal aggregates, and finger-like projections of the cell surface. Promonocytes engage in pinocytosis and phagocytosis, but they are less active in these functions than are peripheral blood monocytes of peritoneal macrophages. Promonocytes are positive for peroxidase, the reaction product being localized to granules most of which are centrally situated in the cell. Monocytes in blood or in inflammatory peritoneal exudates display much smaller numbers of peroxidase-positive granules, and various types of mature mouse macrophages are peroxidase negative.

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