scholarly journals Tissue culture of isolated glomeruli in experimental crescentic glomerulonephritis.

1978 ◽  
Vol 147 (1) ◽  
pp. 98-109 ◽  
Author(s):  
S R Holdsworth ◽  
N M Thomson ◽  
E F Glasgow ◽  
J P Dowling ◽  
R C Atkins
Keyword(s):  
Tissue Culture ◽  
Inflammatory Reaction ◽  
Crescentic Glomerulonephritis ◽  
Mesangial Cells ◽  
Fc Receptors ◽  
Substantial Proportion ◽  
Cell Populations ◽  
Phagocytic Capacity ◽  
Isolated Glomeruli ◽  
Large Numbers

As a means of studying mechanisms of response to injury in glomerulonephritis, glomeruli from normal sheep and rabbits and from sheep and rabbits with experimental crescentic glomerulonephritis have been isolated and grown in tissue culture. The cellular outgrowths from the normal and diseased glomeruli have been compared. The outgrowth of glomeruli from normal animals contained only two cell populations whose microscopic and ultrastructural appearances were of epithelial and mesangial cells. The same cells were also observed in the outgrowths of glomeruli from animals with crescenti nephritis but in addition a third population of cells was present in large numbers. These cells were identified as macrophages by their mobility, ultrastructure, phagocytic capacity, and presence of Fc receptors. Glomerular outgrowth from sheep with crescentic glomerulonephritis contained 170 +/- 20 (SEM) macrophages and outgrowths from rabbits with crescentic nephritis contained 64 +/- 6 (SEM) macrophages per glomerulus. We have previously observed large numbers of macrophages in the outgrowth of isolated glomeruli from humans with rapidly progressive crescentic glomerulonephritis. The predominance of the macrophage in cultures of glomeruli from both human and animal crescentic glomerulonephritis suggests that this is an important cell in the inflammatory reaction occurring in crescentic glomerulonephritis and may comprise a substantial proportion of the cells forming the crescent.

Interactions betweenTrypanosoma bruceiandBabesiaspp. andPlasmodiumspp. in mice

Parasitology ◽  
1985 ◽  
Vol 90 (2) ◽  
pp. 241-254 ◽  
Author(s):  
Stephanie M. Millott ◽  
F. E. G. Cox
Keyword(s):  
Trypanosoma Brucei ◽  
Babesia Microti ◽  
Cell Populations ◽  
Time Interval ◽  
Oxygen Species ◽  
Plasmodium Chabaudi ◽  
Subsequent Infection ◽  
Activated Oxygen ◽  
Large Numbers ◽  
Intracellular Parasites

Swiss mice with chronicTrypanosoma bruceiinfections become refractory to subsequent infection withBabesia microtiandB. rodhaini. Infection withB. microti7 days afterT. bruceiresulted in an obvious inhibition of the babesia parasitaemias and this inhibition became more profound as the time interval between the infections increased, until at 17–20 days the parasitaemias were totally abolished. Even after intravenous injection of large numbers of parasites parasitaemias were inhibited. Similar inhibition was obtained in BALB/c mice but not in C57BL/6 mice. Mice with establishedT. bruceiinfections also showed reduced susceptibility toB. rodhaini. In mice similarly infected withT. bruceiand the malaria parasitesPlasmodium chabaudi chabaudiandP. c. adamithe pre-patent periods were noticeably prolonged but the subsequent parasitaemias were unaffected. Infections withP. yoeliiwere unaffected.Trypanosoma bruceiinfections were not affected by the intracellular parasites. Among the mechanisms investigated to explain these findings were changes in red blood cell populations, cross-reacting antigens, the release of toxic factors and the generation of activated oxygen species. None of these could account for the inhibition observed.

The macrophage capacity for phagocytosis

1992 ◽  
Vol 101 (4) ◽  
pp. 907-913 ◽  
Author(s):  
G.J. Cannon ◽  
J.A. Swanson
Keyword(s):  
Surface Area ◽  
Membrane Surface ◽  
Fc Receptors ◽  
Phagocytic Capacity ◽  
Membrane Surface Area ◽  
Murine Bone Marrow ◽  
Latex Beads ◽  
Endocytic Compartments ◽  
Frustrated Phagocytosis

Murine bone marrow-derived macrophages, which measure 13.8 +/− 2.3 microns diameter in suspension, can ingest IgG-opsonized latex beads greater than 20 microns diameter. A precise assay has allowed the determination of the phagocytic capacity, and of physiological parameters that limit that capacity. Ingestion of beads larger than 15 microns diameter required IgG-opsonization, and took 30 minutes to reach completion. Despite the dependence on Fc-receptors for phagocytosis of larger beads, cells reached their limit before all cell surface Fc-receptors were occupied. The maximal membrane surface area after frustrated phagocytosis of opsonized coverslips was similar to the membrane surface area required to engulf particles at the limiting diameter, indicating that the capacity was independent of particle shape. Vacuolation of the lysosomal compartment with sucrose, which expanded endocytic compartments, lowered the phagocytic capacity. This decrease was reversed when sucrose vacuoles were collapsed by incubation of cells with invertase. These experiments indicate that the phagocytic capacity is limited by the amount of available membrane, rather than by the availability of Fc-receptors. The capacity was also reduced by depolymerization of cytoplasmic microtubules with nocodazole. Nocodazole did not affect the area of maximal cell spreading during frustrated phagocytosis, but did alter the shape of the spread cells. Thus, microtubules may coordinate cytoplasm for engulfment of the largest particles.

scholarly journals ELECTRON MICROSCOPY OF PLASMA-CELL TUMORS OF THE MOUSE

1961 ◽  
Vol 9 (2) ◽  
pp. 369-381 ◽  
Author(s):  
D. F. Parsons ◽  
M. A. Bender ◽  
E. B. Darden ◽  
Guthrie T. Pratt ◽  
D. L. Lindsley
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Complex Structure ◽  
Granular Body ◽  
Virus Particles ◽  
Culture Cells ◽  
Large Numbers ◽  
Tumor Agent

The X5563 tumor has been grown in tissue culture. Cells similar to those of the original tumor migrated from the explant and attached to the glass walls of the culture vessels. Electron microscopy showed that large numbers of particles, similar in morphology to virus particles, were associated with these cells after 7 days of culture. The two principal types of particles found in the tumor in vivo appear to be present in vitro. Many more of these particles, however, were larger and showed a more complex structure. Whereas the particles were mainly localized inside endoplasmic reticulum or the Golgi zone in the tumors in vivo, in the tissue culture the majority of the particles were associated with the plasma membrane and were found outside of the cells. The relation of the particles to the granular body is discussed as well as a possible relation to the mammary tumor agent.

The lymphocyte surface. II. Separation of Fc receptor, C'3 receptor and surface immunoglobulin-bearing lymphocytes

1974 ◽  
Vol 187 (1086) ◽  
pp. 65-81 ◽  
Keyword(s):  
Lymph Nodes ◽  
Thoracic Duct ◽  
Large Population ◽  
Fc Receptors ◽  
Fc Receptor ◽  
Substantial Proportion ◽  
Separation Procedure ◽  
Total Recovery ◽  
Surface Immunoglobulin ◽  
Spleen And Lymph Nodes

A one-step separation procedure is described for both depleting and obtaining in pure form Fc receptor (FcRL), C'3 receptor (CRL) and surface immunoglobulin bearing (IgL) lymphocytes from rat lymphoid populations. The method is a modification of the Bӧyum (1968) technique for separating lymphocytes from whole blood by sedimentation on Ficoll/Isopaque, and is based on the fact that when a lymphocyte forms a rosette with sensitized erythrocytes it will sediment with the red cells rather than float with the non-rosetting lymphocytes. The technique is > 99.5% efficient at depleting thoracic duct lymphocytes (TDL) of FcRL, CRL and IgL and these subpopulations can be recovered 93-98% pure. The total recovery of lymphocytes applied is usually > 90% and the separated lymphocytes are > 95% viable. This technique allowed the cellular distribution of Fc receptors, C'3 receptors and surface Ig to be determined. It was found that ( a ) Almost all CRL carry surface Ig, although a very small sub-population of CRL (0.2-0.8%) which lacks surface Ig could regularly be detected. ( b ) A substantial proportion of IgL (12-25%) lacks C'3 receptors. ( c ) IgL and CRL which lack Fc receptors are more frequent in spleen and lymph nodes than in TDL. The proportion of this subpopulation increases in TDL after prolonged thoracic duct drainage. ( d ) Some FcRL exist which lack both C'3 receptors and surface Ig. These cells are more evident in TDL after prolonged thoracic duct drainage and in lymph nodes (20-30% of FcRL) than in early TDL or spleen (5-10% of FcRL). ( e ) The thymus contains very few FcRL, CRL or IgL. ( f ) A large population of lymphocytes exists in B rats (32-42% of TDL) which is killed by an anti-B serum but which lacks surface Ig. These cells are much less frequent in normal TDL ( < 5%) and probably also lack Fc and C'3 receptors. ( g ) Large lymphocytes probably shed their Fc and C'3 receptors, but retain their surface Ig, during S-phase. ( h ) Studies on a secondary anti-DNP response showed that a substantial proportion of direct and indirect plaque forming cells (PFC) in the spleen express Fc receptors, whereas only indirect PFC carry C'3 receptors. Virtually all PFC ( > 98%) possess surface Ig.

scholarly journals Super-cells untangle large and complex single-cell transcriptome networks

2021 ◽  
Author(s):  
Mariia Bilous ◽  
Loc Tran ◽  
Chiara Cianciaruso ◽  
Santiago J Carmona ◽  
Mikael J Pittet ◽  
...  
Keyword(s):  
Single Cell ◽  
Coarse Graining ◽  
Cell Populations ◽  
Cell Type ◽  
Large Numbers ◽  
Single Cell Rna Sequencing ◽  
Gene Correlation ◽  
Cell Transcriptome ◽  
Single Cell Transcriptome

Single-cell RNA sequencing (scRNA-seq) technologies offer unique opportunities for exploring heterogeneous cell populations. However, in-depth single-cell transcriptomic characterization of complex tissues often requires profiling tens to hundreds of thousands of cells. Such large numbers of cells represent an important hurdle for downstream analyses, interpretation and visualization. Here we develop a network-based coarse-graining framework where highly similar cells are merged into super-cells. We demonstrate that super-cells not only preserve but often improve the results of downstream analyses including visualization, clustering, differential expression, cell type annotation, gene correlation, imputation, RNA velocity and data integration. By capitalizing on the redundancy inherent to scRNA-seq data, super-cells significantly facilitate and accelerate the construction and interpretation of single-cell atlases, as demonstrated by the integration of 1.46 million cells from COVID-19 patients in less than two hours on a standard desktop.

scholarly journals Subcritical Sevastyanov branching processes with nonhomogeneous Poisson immigration

2017 ◽  
Vol 54 (2) ◽  
pp. 569-587 ◽  
Author(s):  
Ollivier Hyrien ◽  
Kosto V. Mitov ◽  
Nikolay M. Yanev
Keyword(s):  
Central Limit Theorem ◽  
Limit Theorem ◽  
Limit Theorems ◽  
Law Of Large Numbers ◽  
Branching Processes ◽  
Asymptotic Properties ◽  
Cell Populations ◽  
Subcritical Case ◽  
Immigration Process ◽  
Large Numbers

Abstract We consider a class of Sevastyanov branching processes with nonhomogeneous Poisson immigration. These processes relax the assumption required by the Bellman–Harris process which imposes the lifespan and offspring of each individual to be independent. They find applications in studies of the dynamics of cell populations. In this paper we focus on the subcritical case and examine asymptotic properties of the process. We establish limit theorems, which generalize classical results due to Sevastyanov and others. Our key findings include a novel law of large numbers and a central limit theorem which emerge from the nonhomogeneity of the immigration process.

scholarly journals Granulocyte Collection by Continuous-flow Filtration Leukapheresis

Blood ◽  
1972 ◽  
Vol 39 (4) ◽  
pp. 554-567 ◽  
Author(s):  
Geoffrey P. Herzig ◽  
Richard K. Root ◽  
Robert G. Graw
Keyword(s):  
Continuous Flow ◽  
Bacterial Infections ◽  
Simple Technique ◽  
Initial Experience ◽  
Differential Centrifugation ◽  
Phagocytic Capacity ◽  
Reversible Adhesion ◽  
Large Numbers ◽  
Flow Filtration

Abstract A safe and simple technique for the collection of large numbers of granulocytes from normal donors, based on the reversible adhesion of granulocytes to nylon wool filters, is described. The procedure is well tolerated by donors, and the granulocytes obtained show nearly normal bactericidal and phagocytic capacity in vitro. However, a surprisingly small median 1-hr posttransfusion increment of 233/cu mm was observed in leukopenic recipients lacking preformed leukocyte antibodies, as compared to the median increment of 850/cu mm reported following transfusion of leukocytes obtained by differential centrifugation. The safety and effectiveness of these granulocytes for the treatment or prevention of bacterial infections in granulocytopenic patients remains to be proven, however our initial experience with such transfusions has been encouraging.

Interaction of immune complexes with Fc receptors in mesangial cells: A potential target for the treatment of IgA nephropathy

Nephrology ◽  
1997 ◽  
Vol 3 (1) ◽  
pp. 95-101 ◽  
Author(s):  
C. GÓMEZ-GUERRERO ◽  
N. DUQUE ◽  
MJ LÓPEZ-ARMADA ◽  
MT CASADO ◽  
F. VIVANCO ◽  
...  
Keyword(s):  
Iga Nephropathy ◽  
Immune Complexes ◽  
Mesangial Cells ◽  
Fc Receptors ◽  
Potential Target

scholarly journals Prolyl Hydroxylase Domain Inhibitor Protects against Metabolic Disorders and Associated Kidney Disease in Obese Type 2 Diabetic Mice

2020 ◽  
Vol 31 (3) ◽  
pp. 560-577 ◽  
Author(s):  
Mai Sugahara ◽  
Shinji Tanaka ◽  
Tetsuhiro Tanaka ◽  
Hisako Saito ◽  
Yu Ishimoto ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Transcriptome Analysis ◽  
Metabolic Disorders ◽  
Mesangial Cells ◽  
Endothelial Damage ◽  
Prolyl Hydroxylase ◽  
Macrophage Infiltration ◽  
Isolated Glomeruli ◽  
Prolyl Hydroxylase Domain

BackgroundProlyl hydroxylase domain (PHD) inhibitors, which stimulate erythropoietin production through the activation of hypoxia-inducible factor (HIF), are novel therapeutic agents used for treating renal anemia. Several PHD inhibitors, including enarodustat, are currently undergoing phase 2 or phase 3 clinical trials. Because HIF regulates a broad spectrum of genes, PHD inhibitors are expected to have other effects in addition to erythropoiesis, such as protection against metabolic disorders. However, whether such beneficial effects would extend to metabolic disorder–related kidney disease is largely unknown.MethodsWe administered enarodustat or vehicle without enarodustat in feed to diabetic black and tan brachyury (BTBR) ob/ob mice from 4 to 22 weeks of age. To elucidate molecular changes induced by enarodustat, we performed transcriptome analysis of isolated glomeruli and in vitro experiments using murine mesangial cells.ResultsCompared with BTBR ob/ob mice that received only vehicle, BTBR ob/ob mice treated with enarodustat displayed lower body weight, reduced blood glucose levels with improved insulin sensitivity, lower total cholesterol levels, higher adiponectin levels, and less adipose tissue, as well as a tendency for lower macrophage infiltration. Enarodustat-treated mice also exhibited reduced albuminuria and amelioration of glomerular epithelial and endothelial damage. Transcriptome analysis of isolated glomeruli revealed reduced expression of C-C motif chemokine ligand 2/monocyte chemoattractant protein-1 (CCL2/MCP-1) in enarodustat-treated mice compared with the vehicle-only group, accompanied by reduced glomerular macrophage infiltration. In vitro experiments demonstrated that both local HIF-1 activation and restoration of adiponectin by enarodustat contributed to CCL2/MCP-1 reduction in mesangial cells.ConclusionsThese results indicate that the PHD inhibitor enarodustat has potential renoprotective effects in addition to its potential to protect against metabolic disorders.

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