Transport in lymphatic capillaries. II. Microscopic velocity measurement with fluorescence photobleaching.
AuthorsBerk DA, Swartz MA, Leu AJ, Jain RK
JournalAm J Physiol
PubMed ID8769769
'Despite its relevance to the physiology of lymph formation and propulsion, the instantaneous flow velocity in single lymphatic capillaries has not been measured to date. The method of fluorescence recovery after photobleaching (FRAP) was adapted for this purpose and used to characterize flow in the lymphatic capillaries in tail skin ... More
Quantitating intracellular transport of polyplexes by spatio-temporal image correlation spectroscopy.
AuthorsKulkarni RP, Wu DD, Davis ME, Fraser SE
JournalProc Natl Acad Sci U S A
PubMed ID15897455
'Quantitatively understanding how nonviral gene delivery vectors (polyplexes) are transported inside cells is essential before they can be optimized for gene therapy and medical applications. In this study, we used spatio-temporal image correlation spectroscopy (ICS) to follow polymer-nucleic acid particles (polyplexes) of various sizes and analyze their diffusive-like and flow ... More
Fractal nature of regional ventilation distribution.
AuthorsAltemeier WA, McKinney S, Glenny RW
JournalJ Appl Physiol
PubMed ID10797111
'High-resolution measurements of pulmonary perfusion reveal substantial spatial heterogeneity that is fractally distributed. This observation led to the hypothesis that the vascular tree is the principal determinant of regional blood flow. Recent studies using aerosol deposition show similar ventilation heterogeneity that is closely correlated with perfusion. We hypothesize that ventilation ... More
Why molecules move along a temperature gradient.
AuthorsDuhr S, Braun D
JournalProc Natl Acad Sci U S A
PubMed ID17164337
'Molecules drift along temperature gradients, an effect called thermophoresis, the Soret effect, or thermodiffusion. In liquids, its theoretical foundation is the subject of a long-standing debate. By using an all-optical microfluidic fluorescence method, we present experimental results for DNA and polystyrene beads over a large range of particle sizes, salt ... More
Central nervous system microglial cell activation and proliferation follows direct interaction with tissue-infiltrating T cell blasts.
AuthorsSedgwick JD, Ford AL, Foulcher E, Airriess R
JournalJ Immunol
PubMed ID9605131
'Central nervous system (CNS)-resident macrophages (microglia) normally express negligible or low level MHC class II, but this is up-regulated in graft-vs-host disease (GvHD), in which a sparse CNS T cell infiltrate is observed. Relative to microglia from the normal CNS, those from the GvHD-affected CNS exhibited a 5-fold up-regulation of ... More
Temporal down-regulation of Fc gamma RIII expression and Fc gamma receptor-mediated phagocytosis in human monocyte-derived macrophages induced by TNF-alpha and IL-1 beta.
AuthorsLiao G, Simon SR
JournalJ Leukoc Biol
PubMed ID8195695
'Effects of tumor necrosis factor (TNF-alpha) and interleukin-1 beta (IL-1 beta) on the expression of Fc gamma receptors (Fc gamma Rs) and on Fc gamma R-mediated phagocytosis in human monocyte-derived macrophages (MDMs) have been determined. Treatment of MDMs with TNF-alpha (400 pg/ml) or IL-1 beta (400 pg/ml) for 80 min ... More
A murine scavenger receptor MARCO recognizes polystyrene nanoparticles.
AuthorsKanno S, Furuyama A, Hirano S,
JournalToxicol Sci
PubMed ID17361018
'Recent toxicological studies indicate that nanoparticles or ultrafine particles (< 100 nm) are more toxic than fine particles (< 2 microm) because of their greater surface area. It is well known that alveolar macrophages play an important role in the first defense against various environmental particles and microorganisms. This is ... More
Super-resolution video microscopy of live cells by structured illumination.
AuthorsKner P, Chhun BB, Griffis ER, Winoto L, Gustafsson MG,
JournalNat Methods
PubMed ID19404253
Structured-illumination microscopy can double the resolution of the widefield fluorescence microscope but has previously been too slow for dynamic live imaging. Here we demonstrate a high-speed structured-illumination microscope that is capable of 100-nm resolution at frame rates up to 11 Hz for several hundred time points. We demonstrate the microscope ... More
Regulation of phagosome maturation by signals from toll-like receptors.
AuthorsBlander JM, Medzhitov R
JournalScience
PubMed ID15143282
In higher metazoans, phagocytosis is essential in host defense against microbial pathogens and in clearance of apoptotic cells. Both microbial and apoptotic cells are delivered on a common route from phagosomes to lysosomes for degradation. Here, we found that activation of the Toll-like receptor (TLR) signaling pathway by bacteria, but ... More
LPS receptor (CD14): a receptor for phagocytosis of Alzheimer's amyloid peptide.
AuthorsLiu Y, Walter S, Stagi M, Cherny D, Letiembre M, Schulz-Schaeffer W, Heine H, Penke B, Neumann H, Fassbender K,
JournalBrain
PubMed ID15857927
The amyloid beta peptide 42 (Abeta(42)) plays a key role in neurotoxicity in Alzheimer's disease. Mononuclear phagocytes, i.e. microglia, have the potential to clear Abeta by phagocytosis. Recently, the lipopolysaccharide (LPS) receptor CD14 was shown to mediate phagocytosis of bacterial components and furthermore to contribute to neuroinflammation in Alzheimer's disease. ... More
Heterogeneity in macrophage phagocytosis of Staphylococcus aureus strains: high-throughput scanning cytometry-based analysis.
AuthorsDeLoid GM, Sulahian TH, Imrich A, Kobzik L,
JournalPLoS One
PubMed ID19593389
Alveolar macrophages (AMs) can phagocytose unopsonized pathogens such as S. aureus via innate immune receptors, such as scavenger receptors (SRs). Cytoskeletal events and signaling pathways involved in phagocytosis of unopsonized bacteria likely govern the fate of ingested pathogens, but are poorly characterized. We have developed a high-throughput scanning cytometry-based assay ... More
Live-cell superresolution imaging by pulsed STED two-photon excitation microscopy.
AuthorsTakasaki KT, Ding JB, Sabatini BL,
JournalBiophys J
PubMed ID23442955
Two-photon laser scanning microscopy (2PLSM) allows fluorescence imaging in thick biological samples where absorption and scattering typically degrade resolution and signal collection of one-photon imaging approaches. The spatial resolution of conventional 2PLSM is limited by diffraction, and the near-infrared wavelengths used for excitation in 2PLSM preclude the accurate imaging of ... More
Collection, focusing, and metering of DNA in microchannels using addressable electrode arrays for portable low-power bioanalysis.
AuthorsShaikh FA, Ugaz VM
JournalProc Natl Acad Sci U S A
PubMed ID16551750
Although advances in microfluidic technology have enabled increasingly sophisticated biosensing and bioassay operations to be performed at the microscale, many of these applications employ such small amounts of charged biomolecules (DNA, proteins, and peptides) that they must first be preconcentrated to a detectable level. Efficient strategies for precisely handling minute ... More
Detection of changes occurring during recovery from the dauer stage in Heterorhabditis bacteriophora.
AuthorsDolan KM, Jones JT, Burnell AM
JournalParasitology
PubMed ID12166523
Nematodes of the genus Heterorhabditis are insect parasites that are widely used as biological control agents. When conditions are unfavourable for reproduction in H. bacteriophora, a long-lived, non-feeding, survival and dispersal stage, the dauer juvenile (DJ), is formed. This DJ stage is also adapted for host finding and infection. When ... More
Effect of lentinan and mannan on phagocytosis of fluorescent latex microbeads by mouse peritoneal macrophages: a flow cytometric study.
AuthorsAbel G, Szöllösi J, Chihara G, Fachet J
JournalInt J Immunopharmacol
PubMed ID2807634
Lentinan, an immunopotentiating beta-1,3-glucan polysaccharide stimulated the in vitro phagocytosis of BSA-coated, C3b- or monoclonal immunoglobulin (IgG2b)-coated fluorescent microspheres by resident or thioglycollate-elicited mouse macrophages in a dose-dependent manner. Analysis of flow cytometric data has shown that microbead phagocytosis of resident macrophages, which exhibit a lower basic phagocytic activity than ... More
Differentiation of monocytic cell clones into CD8 alpha+ dendritic cells (DC) suggests that monocytes can be direct precursors for both CD8 alpha+ and CD8 alpha- DC in the mouse.
AuthorsGao JX, Liu X, Wen J, Zhang H, Durbin J, Liu Y, Zheng P
JournalJ Immunol
PubMed ID12794119
Dendritic cells (DC) are the professional APCs that initiate T cell immune responses. DC can develop from both myeloid and lymphoid progenitors. In the mouse, the CD8alpha(+) DC had been designated as "lymphoid" DC, and CD8alpha(-) DC as "myeloid" DC until recently when it was demonstrated that common myeloid progenitors ... More
Computer image analysis method for rapid quantitation of macrophage phagocytosis.
AuthorsOdeyale CO, Hook GR
JournalJ Leukoc Biol
PubMed ID2121881
A new method is described for rapidly quantitating phagocytosis by adherent macrophages in culture using computer image analysis (CIA) of video light microscopic images. Ingestion of fluorescent microspheres by peritoneal murine macrophages is used to model phagocytosis. The grey levels of digital phase contrast and fluorescent microscopic images are used ... More
Critical role of the alpha 4 integrin/VCAM-1 pathway in cerebral leukocyte trafficking in lupus-prone MRL/fas(lpr) mice.
AuthorsJames WG, Bullard DC, Hickey MJ
JournalJ Immunol
PubMed ID12496439
MRL/fas(lpr) mice are affected by a systemic autoimmune disease that results in leukocyte recruitment to a wide range of vascular beds, including the cerebral microvasculature. The mechanisms responsible for the leukocyte trafficking to the brain in these animals are not known. Therefore, the aim of this study was to directly ... More