scholarly journals Localization of submembranous cations to the leading end of human neutrophils during chemotaxis.

1979 ◽  
Vol 82 (2) ◽  
pp. 369-379 ◽  
Author(s):  
E B Cramer ◽  
J I Gallin
Keyword(s):  
Cell Membrane ◽  
Leading Edge ◽  
Human Neutrophils ◽  
X Ray ◽  
Random Migration ◽  
Small Pore ◽  
Chemotactic Factors ◽  
Cytoplasmic Side ◽  
Granule Release ◽  
Potassium Pyroantimonate

Potassium pyroantimonate was used to localize sites of bound cations in human neutrophils under conditions of random migration, stimulated random migration (chemokinesis), and directed migration (chemotaxis). The cells were placed in a standard chamber in which 0.45-micron micropore filters separated the cells from the stimulus (buffer, Escherichia coli endotoxin-activated serum or the synthetic chemotactic peptide N-formyl-Met-Leu-Phe). The small pore filters permitted pseudopod formation but impeded cell imgration through the filter. Cells examined under all conditions had electron-dense precipitates of antimonate salts in some granules. However, antimonate deposits were localized in the condensed chromatin of the nucleus during random migration and associated to a large extent with the uncondensed nuclear chromatin during chemokinesis and chemotaxis. Under conditions of chemokinesis deposition of antimonate procipitates appeared on the cytoplasmic side of the plasma membrane of neutrophils whereas under conditions of chemotaxis cation deposits beneath the cell membrane were localized to the pseudopods which were directed toward the chemoattractant. In addition to endotoxin-activated serum, concentrations of N-formyl-Met-Leu-Phe which caused neutrophil chemotaxis (10(-8) M) also caused cation deposition beneath the cell membrane at the leading end of the cell regardless of whether albumin was present in the incubation media. However, with higher concentrations of the synthetic peptide (10(-5) M) which caused granule release and were not chemotactic, submembranous cation deposition was not seen. EDTA (10 mM) and EGTA (10 mM) removed nuclear, granular, and submembranous cation deposits from neutrophils examined under conditions of chemotaxis. X-ray microprobe analysis of antimonate deposits revealed the possible presence of calcium but did not detect sodium or magnesium. The data indicate that chemotactic factors induce submembranous deposition of cations, most likely Ca++, which localize to the leading edge of cells exposed to a gradient of chemoattractant.

scholarly journals Structural analysis of human neutrophil migration: Centriole, microtubule, and microfilament orientation and function during chemotaxis

1977 ◽  
Vol 75 (3) ◽  
pp. 666-693 ◽  
Author(s):  
HL Malech ◽  
RK Root ◽  
JI Gallin
Keyword(s):  
Cytochalasin B ◽  
Neutrophil Migration ◽  
Solid Substrate ◽  
Human Neutrophils ◽  
Random Migration ◽  
Filter Surface ◽  
Functional Studies ◽  
Small Pore ◽  
And Migration ◽  
Linear Alignment

Orientation of nucleus, centriole, microtubules, and microfilaments within human neutrophils in a gradient of chemoattractant (5 percent Escherichia coli endotoxin-activated serum) was evaluated by electron microscopy. Purified neutropils (hypaque-Ficoll) were placed in the upper compartment of chemotactic chambers. Use of small pore (0.45 μm) micropore filters permitted pseudopod penetration, but impeded migration. Under conditions of chemotaxis with activated serum beneath the filter, the neutrophil population oriented at the filter surface with nuclei located away from the stimulus, centrioles and associated radial array of microtubules beneath the nuclei, and microfilament-rich pseudopods penetrating the filter pores. Reversal of the direction of the gradient of the stimulus (activated serum above cells) resulted in a reorientation of internal structure which preceded pseudopod formation toward the activated serum and migration off the filter. Coordinated orientation of the entire neutrophil population did not occur in buffer (random migration) or in a uniform concentration of activated serum (activated random migration). Conditions of activated random migration resulted in increased numbers of cells with locomotory morphology, i.e. cellular asymmetry with linear alignment of nucleus, centriole, microtubule array, and pseudopods. Thus, activated serum increased the number of neutrophils exhibiting locomotory morphology, and a gradient of activated serum induced the alignment of neutrophils such that this locomotory morphology was uniform in the observed neutrophil populayion. In related studies, cytochalasin B and colchicines were used to explore the role of microfilaments and microtubules in the neutrophil orientation and migration response to activated serum. Cytochalasin B (3.0 μg/ml) prevented migration and decreased the microfilaments seen, but allowed normal orientation of neutrophil structures. In an activated serum gradient, colchicines, but not lumicolchicine, decreased the orientation of nuclei and centrioles, and caused a decrease in centriole-associated microtubules in concentrations as low as 10(-8) to 10(-7) M. These colchicines effects were associated with the rounding of cells and impairment of pseudopod formation. The impaired pseudopod formation was characterized by an inability to form pseudopods in the absence of a solid substrate, a formation of narrow pseudopods within a substrate, and a defect in pseudopod orientation in an activated serum gradient. Functional studies of migration showed that colchicines, but not lumicolchicine, minimally decreased activated random migration and markedly inhibited directed migration, but had not effect on random migration. These studies show that, although functioning microfilaments are probably necessary for neutrophil migration, intact microtubules are essential for normal pseudopod formation and orientation, and maximal unidirectional migration during chemotaxis.

The Inhibitory Effect of Heparin and Related Glycosaminoglycans on Neutrophil Chemotaxis

1984 ◽  
Vol 52 (02) ◽  
pp. 134-137 ◽  
Author(s):  
Yaacov Matzner ◽  
Gerard Marx ◽  
Ruth Drexler ◽  
Amiram Eldor
Keyword(s):  
Specific Binding ◽  
Anticoagulant Activity ◽  
Neutrophil Migration ◽  
Inhibitory Effect ◽  
Chemotactic Factor ◽  
Human Neutrophils ◽  
Boyden Chamber ◽  
Neutrophil Chemotaxis ◽  
Inhibitory Effects ◽  
Chemotactic Factors

SummaryClinical observations have shown that heparin has antiinflammatory activities. The effect of heparin on neutrophil chemotaxis was evaluated in vitro in the Boyden Chamber. This method enabled differentiation between the direct effects of heparin on neutrophil migration and locomotion, and its effects on chemotactic factors. Heparin inhibited both the random migration and directed locomotion of human neutrophils toward zymosan-activated serum (ZAS) and F-met-leu-phe (FMLP). Inhibition was found to be dependent on the concentrations of the heparin and of the chemotactic factors. No specific binding of heparin to the neutrophils could be demonstrated, and heparin’s inhibitory effects were eliminated by simple washing of the cells. When added directly to the chamber containing chemotactic factor, heparin inhibited the chemotactic activity of ZAS but not that of FMLP, suggesting a direct inhibitory effect against C5a, the principal chemotactic factor in ZAS.Experiments performed with low-molecular-weight heparin, N-desulfated heparin, dextran sulfate, chondroitin sulfate and dextran indicated that the inhibitory effects of heparin on neutrophil chemotaxis are not related to its anticoagulant activity, but probably depend on the degree of sulfation of the heparin molecule.

scholarly journals A case of pleuroperitoneal communication in which establishing a laparoscopic pneumoperitoneum was useful for the detection of a fistula

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Takehiko Manabe ◽  
Kenji Ono ◽  
Soichi Oka ◽  
Yuichiro Kawamura ◽  
Toshihiro Osaki
Keyword(s):  
Thoracic Surgery ◽  
Surgical Repair ◽  
Abdominal Cavity ◽  
Case Presentation ◽  
X Ray ◽  
Video Assisted Thoracic Surgery ◽  
Video Assisted ◽  
Pleuroperitoneal Communication ◽  
Small Pore ◽  
Chest X Ray

Abstract Background Pleuroperitoneal communication (PPC) is rarely observed, accounting for 1.6% of all patients who undergo continuous ambulatory peritoneal dialysis (CAPD). Although there have been several reports concerning the management of this condition, we have encountered several cases in which control failed. We herein report a valuable case of PPC in which laparoscopic pneumoperitoneum with video-assisted thoracic surgery (VATS) was useful for supporting the diagnosis and treatment. Case presentation The patient was a 58-year-old woman with chronic renal failure due to chronic renal inflammation who was referred to a nephrologist in our hospital to undergo an operation for the induction of CAPD. Post-operatively, she had respiratory failure, and chest X-ray and computed tomography (CT) showed right-sided hydrothorax that decreased when the injection of peritoneal dialysate was interrupted. Therefore, PPC was suspected, and she was referred to our department for surgical repair. We planned surgical treatment via video-assisted thoracic surgery. During the surgery, we failed to detect any lesions with thoracoscopy alone; we therefore added a laparoscopic port at her right-sided abdomen near the navel and infused CO2 gas into the abdominal cavity. On thoracoscopy, bubbles were observed emanating from a small pore at the central tendon of the diaphragm, which was considered to be the lesion responsible for the PPC. We closed it by suturing directly. Conclusions VATS with laparoscopic pneumoperitoneum should be considered as an effective method for inspecting tiny pores of the diaphragm, especially when the lesions responsible for PPC are difficult to detect.

scholarly journals A Staged Approach to Erosion Analysis of Wind Turbine Blade Coatings

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 681
Author(s):  
David Nash ◽  
Grant Leishman ◽  
Cameron Mackie ◽  
Kirsten Dyer ◽  
Liu Yang
Keyword(s):  
Computed Tomography ◽  
Wind Turbine ◽  
Incubation Period ◽  
Leading Edge ◽  
X Ray ◽  
Erosion Testing ◽  
Staged Approach ◽  
X Ray Computed ◽  
Droplet Impacts ◽  
Rain Erosion

The current wind turbine leading-edge erosion research focuses on the end of the incubation period and breakthrough when analysing the erosion mechanism. This work presented here shows the benefits of splitting and describing leading-edge erosion progression into discrete stages. The five identified stages are: (1) an undamaged, as-new, sample; (2) between the undamaged sample and end of incubation; (3) the end of incubation period; (4) between the end of incubation and breakthrough, and (5) breakthrough. Mass loss, microscopy and X-ray computed tomography were investigated at each of the five stages. From this analysis, it was observed that notable changes were detected at Stages 2 and 4, which are not usually considered separately. The staged approach to rain erosion testing offers a more thorough understanding of how the coating system changes and ultimately fails due to rain droplet impacts. It is observed that during microscopy and X-ray computed tomography, changes unobservable to the naked eye can be tracked using the staged approach.

scholarly journals Chloride Movements in Human Neutrophils during Phagocytosis: Characterization and Relationship to Granule Release

2007 ◽  
Vol 179 (6) ◽  
pp. 4110-4124 ◽  
Author(s):  
Sara Busetto ◽  
Elisa Trevisan ◽  
Eva Decleva ◽  
Pietro Dri ◽  
Renzo Menegazzi
Keyword(s):  
Human Neutrophils ◽  
Granule Release

Single Crystal X-ray Diffraction Studies of Carbon Dioxide and Fuel-Related Gases Adsorbed on the Small Pore Scandium Terephthalate Metal Organic Framework, Sc2(O2CC6H4CO2)3

Langmuir ◽  
2009 ◽  
Vol 25 (6) ◽  
pp. 3618-3626 ◽  
Author(s):  
Stuart R. Miller ◽  
Paul A. Wright ◽  
Thomas Devic ◽  
Christian Serre ◽  
Gérard Férey ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Single Crystal ◽  
Metal Organic Framework ◽  
X Ray Diffraction ◽  
X Ray ◽  
Small Pore ◽  
Metal Organic ◽  
Organic Framework

scholarly journals K-paracelsian (KAlSi3O8·H2O) and identification of a simple building scheme of dense double-crankshaft zeolite topologies

IUCrJ ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 66-71 ◽  
Author(s):  
Cristian-R. Boruntea ◽  
Peter N. R. Vennestrøm ◽  
Lars F. Lundegaard
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Space ◽  
Ex Situ ◽  
Zeolite Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Conditions ◽  
Small Pore ◽  
Scanning Electron

During screening of the phase space using KOH and 1-methyl-4-aza-1-azoniabicyclo[2.2.2]octane hydroxide (1-methyl-DABCO) under hydrothermal zeolite synthesis conditions, K-paracelsian was synthesized. Scanning electron microscopy, energy dispersive X-ray spectroscopy and ex situ powder X-ray diffraction analysis revealed a material that is compositionally closely related to the mineral microcline and structurally closely related to the mineral paracelsian, both of which are feldspars. In contrast to the feldspars, K-paracelsian contains intrazeolitic water corresponding to one molecule per cage. In the case of K-paracelsian it might be useful to consider it a link between feldspars and zeolites. It was also shown that K-paracelsian can be described as the simplest endmember of a family of dense double-crankshaft zeolite topologies. By applying the identified building principle, a number of known zeolite topologies can be constructed. Furthermore, it facilitates the construction of a range of hypothetical small-pore structures that are crystallo-chemically healthy, but which have not yet been realized experimentally.

X-Ray and Fluorescence Studies on Phospholipid Bilayers. IX. Interactions with Pentachlorophenol

1990 ◽  
Vol 45 (3-4) ◽  
pp. 265-272 ◽  
Author(s):  
M. Suwalsky ◽  
M. A. Espinoza ◽  
M. Bagnara ◽  
C. P. Sotomayor
Keyword(s):  
Cell Membrane ◽  
Phospholipid Bilayers ◽  
Erythrocyte Membranes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fluorescence Studies ◽  
Human Erythrocyte Membranes ◽  
Cell Membrane Level ◽  
Membrane Level ◽  
Sodium Form

Abstract Pentachlorophenol (PCP) is a widely used and highly toxic fungicide. Its toxicity is mainly expressed at the cell membrane level. It is, therefore, of interest to test its ability to alter the lipid bilayer organization. The present study was performed by X-ray diffraction techniques on dimyristoylphosphatidylethanolamine (DMPE) and dimyristoylphosphatidylcholine (DMPC) bilayers and by fluorescence on DMPC liposomes. These two phospholipids are respectively found at the inner and outer monolayers of human erythrocyte membranes. Each type of phospholipid was made to interact with different concentrations of the sodium form of PCP in absence and in presence of water. It was found that PCP significatively affected the structure of both phospholipids, being the damage much higher in DM PC bilayers.

scholarly journals Antituberculosis Drug Interactions with Membranes: A Biophysical Approach Applied to Bedaquiline

Membranes ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 141
Author(s):  
Marina Pinheiro ◽  
Heinz Amenitsch ◽  
Salette Reis
Keyword(s):  
Cell Membrane ◽  
Eukaryotic Cell ◽  
Membrane Model ◽  
Molar Ratio ◽  
X Ray ◽  
X Ray Scattering ◽  
Membrane Models ◽  
Bacterial Cell Membrane ◽  
Cell Membrane Model ◽  
Ray Scattering

This work focuses on the interaction of the novel and representative antituberculosis (anti-TB) drug bedaquiline (BDQ) with different membrane models of eukaryotic and prokaryotic cells. The effect of BDQ on eukaryotic cell membrane models was assessed using liposomes, namely, multilamellar vesicles (MLVs) made of 1,2-dimyristoyl-rac-glycero-3-phosphocholine (DMPC) and also a mixture of DMPC and cholesterol (CHOL) (8:2 molar ratio). To mimic the prokaryotic cell membrane, 1,2-dimyristoyl-sn-glycero-3-phospho-rac-(1-glycerol) (DMPG) and 1,1′2,2′-tetra-oleoyl-cardiolipin (TOCL) were chosen. Powerful biophysical techniques were employed, including small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS), to understand the effect of BDQ on the nanostructure of the membrane models. The results showed that BDQ demonstrated a pronounced disordering effect in the bacterial cell membrane models, especially in the membrane model with cardiolipin (CL), while the human cell membrane model with large fractions of neutral phospholipids remained less affected. The membrane models and techniques provide detailed information about different aspects of the drug–membrane interaction, thus offering valuable information to better understand the effect of BDQ on their target membrane-associated enzyme as well as its side effects on the cardiovascular system.

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