Effect of antiplatelet antibody on platelet shape change, volume, and morphology

1983 ◽  
Vol 244 (3) ◽  
pp. H357-H361 ◽  
Author(s):  
R. W. Colman ◽  
V. T. Nachmias ◽  
D. B. Cines ◽  
A. D. Schreiber
Keyword(s):  
Electron Microscopy ◽  
Morphological Changes ◽  
Shape Change ◽  
Human Platelets ◽  
Antibody Concentration ◽  
Platelet Volume ◽  
Antiplatelet Antibody ◽  
Specific Effects ◽  
Transmission Electron ◽  
Platelet Shape

We extended our studies of the effect of antibody on human platelets. Monomeric immunoglobulin G (IgG) (rabbit) antiplatelet antibody was interacted with human platelets in the absence of complement and the early morphological changes monitored. Platelet shape change, assessed by a rheooptical approach, was noted within 20 s and was proportional to antibody concentration. Antiplatelet antibody-induced shape change was also accompanied by a change in apparent platelet volume, as measured in the resistive particle counter. Scanning and transmission electron microscopy confirmed a disk-to-sphere transformation associated with the formation of bulbous, short surface projections or pseudopodia. In contrast, ADP-induced disk-to-sphere transformation was associated with the development of long, thin filopodia emanating from the platelet. These specific effects of antiplatelet antibody may result in altered platelet function.

Pre-Aggregation changes in plate let volume

1979 ◽  
Author(s):  
A.R.L. Gear
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mean Platelet Volume ◽  
Morphological Changes ◽  
Temperature Cycling ◽  
Platelet Volume ◽  
Before And After ◽  
Subsequent Exposure ◽  
Scanning Electron ◽  
Platelet Shape

Previous research on whether platelet volume increases durinq the morphological changes precedinq aqqregation is controversial; resistive-countinq techniques reveal an increase, centrifugal methods do noL. A computerized, resistive-particle counter has therefore been used to size platelets before and after incubation with ADP. The effects of EDIA and centrifugation were also evaluated. ADP (2 mH) significantly increased mean platelet volume from 4.81 to 5.47(p<.001). CDIA (2 mM) inhibited this increase by 50%, and both centrifugation and EDIA also caused platelet swelling.Platelet shape was experimentally manipulated with colchicine, chlorpromazine and temperature cycling, to test the hypothesis that changes in resistive-volume stem from artifacts of particle shape. Scanning-electron microscopy confirmed that these treatments caused extensive sphering of disc-shaped platelets. However, subsequent exposure to ADP resulted in major increases in resistive volume, and in the case of chlorpromazine, no pseudopodia were extruded. It is concludedthat platelet volume can increase durinq pre-aqqreqation reactions, and that earlier research based on centri-Tuqation in the presence of EDIA failed tn reveal the increase because of inhibitory and swelling effects. This work mas supported, in part, by PHS Grants AM-20727, HL-1S289, and HL-7D759.

Platelet Shape Change And Cytoskeletal Reorientation During Adhesion And Spreading

1981 ◽  
Author(s):  
J C Mattson
Keyword(s):  
Shape Change ◽  
Human Platelets ◽  
Cytoskeletal Organization ◽  
Transmission Electron ◽  
Ionic Detergent ◽  
Filament Bundles ◽  
Trabecular Network ◽  
Surface Web ◽  
Whole Mounts ◽  
Platelet Shape

Sequential morphologic and cytoskeletal changes which occur during platelet adhesion have been examined by transmission electron microscopy of detergent extracted whole mounts. Human platelets allowed to spread on formvar-coated grids for 5, 15, 30 or 60 min. were fixed in glut- araldehyde to which the non-ionic detergent Nonedet P40 had been added. Whole mounts examined after 5 min. of contact demonstrated “dendritic platelets” with centralized organelles and numerous elongated pseudopodia. The cytoskeletal organization was oriented around the pseudopodia with bundles of 60-120 Å filaments extending into each pseudopod. At the base of many pseudopodia dense filamentous mats measuring from 0.2-0.5 μ were intimately associated with the filament bundles; filaments appeared to radiate from filament mats producing stellate configurations. An underlying trabecular network of 30-85 Å filaments was present interconnecting the longer filaments. The microtubular coil usually associated with the centralized granulomere of aggregated platelets appeared to uncoil in adherent platelets. As adhesion progressed, platelets were seen to spread on the formvar surface. Web-like extensions of platelet cytoplasm filled in and connected pseudopodia eventually replacing these processes with large veils of extended cytoplasm. By 60 min. most platelets were completely spread and had circular, fanshaped or polygonal configurations. Radially oriented filament bundles extending from dense filament mats remained visible in the cytoplasmic veils of early spreading platelets, but as spreading progressed reorganization of filaments and filament mats occurred. Filament mats, in more completely spread platelets, were present at the platelet margin and filament bundles were no longer radially oriented but assumed a circumferential organization surrounding the centralized platelet granules. These studies demonstrate that cytoskeletal reorganization is intimately associated with the platelet shape change.

Ultrastructural Study of Rat Colon Following Psyllium Ingestion

1985 ◽  
Vol 43 ◽  
pp. 580-581
Author(s):  
F.G. Lightfoot ◽  
L.E. Grau ◽  
M.M. Cassidy ◽  
G.R. Tadvalkar ◽  
G.V. Vahouny
Keyword(s):  
Electron Microscopy ◽  
Morphological Changes ◽  
Large Population ◽  
Rat Colon ◽  
Gastrointestinal Disorders ◽  
Luminal Surface ◽  
Fecal Material ◽  
Transmission Electron ◽  
Morphologic Analysis ◽  
Irritable Bowel

Psyllium hydrophillic mucilloid is a natural gelling fiber consumed by a large population of our society. It is used as a bulk-producing laxative and in the treatment of gastrointestinal disorders such as “Irritable Bowel Syndrome”. The literature pertaining to the ultrastructural effects of this agent is sparse.This study documents morphological changes induced by psyllium. Animals fed a diet containing 2% psyllium for four weeks were subsequently sacrificed and processed for scanning and transmission electron microscopy. The colon contained fecal material combined with psyllium which conformed to the contour of the luminal surface. This mixture formed surface replicas of the intestinal mucosa. These replicas and their related colonic sites were processed for morphologic analysis.

Correlation Between Cellular Functions and Morphological Changes of Human Trophoblast in Vitro

1975 ◽  
Vol 33 ◽  
pp. 600-601
Author(s):  
John C. Garancis ◽  
Robert O. Hussa ◽  
Michael T. Story ◽  
Donald Yorde ◽  
Roland A. Pattillo
Keyword(s):  
Electron Microscopy ◽  
Cellular Proliferation ◽  
Morphological Changes ◽  
Culture Fluid ◽  
Cellular Functions ◽  
Human Trophoblast ◽  
Transmission Electron ◽  
Marked Activity ◽  
Malignant Trophoblast

Human malignant trophoblast cells in continuous culture were incubated for 3 days in medium containing 1 mM N6-O2'-dibutyryl cyclic adenosine 3':5'-monophosphate (dibutyryl cyclic AMP) and 1 mM theophylline. The culture fluid was replenished daily. Stimulated cultures secreted many times more chorionic gonadotropin and estrogens than did control cultures in the absence of increased cellular proliferation. Scanning electron microscopy revealed remarkable surface changes of stimulated cells. Control cells (not stimulated) were smooth or provided with varying numbers of microvilli (Fig. 1). The latter, usually, were short and thin. The surface features of stimulated cells were considerably different. There was marked increase of microvilli which appeared elongated and thick. Many cells were covered with confluent polypoid projections (Fig. 2). Transmission electron microscopy demonstrated marked activity of cytoplasmic organelles. Mitochondria were increased in number and size; some giant forms with numerous cristae were observed.

Physiological Effects of Nonimmune Platelet Associated Immunoglobulin G

1981 ◽  
Vol 45 (01) ◽  
pp. 027-033 ◽  
Author(s):  
K Sugiura ◽  
M Steiner ◽  
M Baldini
Keyword(s):  
Shape Change ◽  
Fluorescein Isothiocyanate ◽  
Recovery Phase ◽  
Human Platelets ◽  
Serotonin Release ◽  
Platelet Volume ◽  
Igg Antibody ◽  
Heterologous Antiserum ◽  
Igg Binding ◽  
Series Of Experiments

SummaryThe function of nonimmune IgG associated with platelets is unknown. In a series of experiments we have investigated this problem, relating amount of platelet-associated IgG (PAIgG) to platelet volume, serotonin release, adherence of platelets to monocytes and platelet senescence. Most of these studies were performed with human platelets. Platelets freed of preexisting PAIgG by incubation at 22° C were incubated with IgG in a series of concentrations ranging from 0.4 — 27.0 X10-6 M. The IgG preparations used were demonstrably free of aggregated forms of the protein. The amount of PAIgG bound to platelets was determined by the use of fluorescein isothiocyanate-conjugated anti-IgG antibody (F-anti-IgG antibody) which was quantified in a fluorospectrophotometer. Newly bound IgG was assayed similarly by the use of F-IgG. A dose-dependent increase in platelet volume was associated with the binding of nonimmune IgG by platelets. The process which leveled off at an IgG concentration of 1.2 —1.5 X10-5 M was almost fully reversible and was not due to platelet shape change or aggregation. Release of serotonin from IgG-treated platelets was relatively small but to the extent that it occurred was positively related to the IgG concentration to which platelets were exposed. Adherence to autologous monocytes studied quantitatively by the use of formaldehyde-fixed cells was also positively related to the amount of IgG on the platelets. Normal or IgG-defident serum had a potent inhibitory (noncompetitive) action on the binding of F-IgG and F-anti-human IgG antibody to human platelets. Cohorts of platelets prepared in rabbits during the recovery phase of immunological thrombocytopenia induced by injection of heterologous antiserum, showed an age-dependent increase of PAIgG and of IgG binding. These results suggest that PAIgG plays a role in the clearance of senescent platelets.

scholarly journals Zinc Oxide and Silver Nanoparticle Effects on Intestinal Bacteria

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2489
Author(s):  
Ami Yoo ◽  
Mengshi Lin ◽  
Azlin Mustapha
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Morphological Changes ◽  
Intestinal Bacteria ◽  
Bacterial Cells ◽  
Ag Nps ◽  
Zno Nps ◽  
Bifidobacterium Animalis ◽  
Transmission Electron

The application of nanoparticles (NPs) for food safety is increasingly being explored. Zinc oxide (ZnO) and silver (Ag) NPs are inorganic chemicals with antimicrobial and bioactive characteristics and have been widely used in the food industry. However, not much is known about the behavior of these NPs upon ingestion and whether they inhibit natural gut microflora. The objective of this study was to investigate the effects of ZnO and Ag NPs on the intestinal bacteria, namely Escherichia coli, Lactobacillus acidophilus, and Bifidobacterium animalis. Cells were inoculated into tryptic soy broth or Lactobacilli MRS broth containing 1% of NP-free solution, 0, 12, 16, 20 mM of ZnO NPs or 0, 1.8, 2.7, 4.6 mM Ag NPs, and incubated at 37 °C for 24 h. The presence and characterization of the NPs on bacterial cells were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). Membrane leakage and cell viability were assessed using a UV-visible spectrophotometer and confocal electron microscope, respectively. Numbers of treated cells were within 1 log CFU/mL less than those of the controls for up to 12 h of incubation. Cellular morphological changes were observed, but many cells remained in normal shapes. Only a small amount of internal cellular contents was leaked due to the NP treatments, and more live than dead cells were observed after exposure to the NPs. Based on these results, we conclude that ZnO and Ag NPs have mild inhibitory effects on intestinal bacteria.

scholarly journals Human serum activates the tegument of female schistosomes and supports recovery from Praziquantel

2020 ◽  
Author(s):  
Franziska Winkelmann ◽  
Marcus Frank ◽  
Anne Rabes ◽  
Nicole Koslowski ◽  
Cindy Schulz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Human Serum ◽  
Immune Reaction ◽  
Morphological Changes ◽  
Expression Profiles ◽  
Female Worm ◽  
Male Worm ◽  
Transmission Electron ◽  
Gene Expression Analyses ◽  
Males And Females

AbstractSchistosomiasis is one of the most devastating parasitic disease in the world. Schistosoma spp. survive for decades within the vasculature of their human hosts. They have evolved a vast array of mechanisms to avoid the immune reaction of the host. Due to their sexual dimorphism, with the female worm lying within the gynecophoric canal of the male worm, it is the male that is exposed to the immediate environment and the soluble parts of the host’s immune response. To understand how the worms are so successful in fending off the immune attacks of the host, comparative analyses of both worm sexes in human serum (with or without Praziquantel) were performed using scanning electron microscopy, transmission electron microscopy, and immunohistochemistry. Further, gene expression analyses of tegument-specific genes were performed. Following the incubation in human serum, males and females out of pairs show morphological changes such as an altered structure of the pits below the surface and an increased number of pits per area. In addition, female schistosomes presented a marked tuft-like repulsion of their opsonized surface. The observed resistance of females to Praziquantel seemed to depend on active proteins in the human serum. Moreover, different expression profiles of tegument-specific genes indicate different functions of female_single and male_single teguments in response to human serum. Our results indicate that female schistosomes developed different evasion strategies toward the host’s immune system in comparison to males that might lead to more robustness and has to be taken into account for the development of new anti-schistosomal drugs.

scholarly journals Cytochemical localization of calcium and Ca2+,Mg2(+)-adenosine triphosphatase in colchicine-altered rat incisor ameloblasts.

1990 ◽  
Vol 38 (10) ◽  
pp. 1469-1478 ◽  
Author(s):  
D R Eisenmann ◽  
A H Salama ◽  
A M Zaki ◽  
S H Ashrafi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Adenosine Triphosphatase ◽  
Morphological Changes ◽  
Rat Incisor ◽  
Cytochemical Localization ◽  
Early Maturation ◽  
Transmission Electron ◽  
Maturation Stages ◽  
Secretory Transport

Colchicine is known to affect secretory, transport, and degradative functions of ameloblasts. The effects of colchicine on membrane-associated calcium and Ca2+,Mg2(+)-ATPase in secretory and maturation ameloblasts were investigated cytochemically. The pyroantimonate (PPA) method was used for localizing calcium and a modified Wachstein-Meisel medium was used to localize Ca2+,Mg2(+)-ATPase. Sections representing secretory and early maturation stages were examined by transmission electron microscopy. Morphological changes induced by colchicine included dislocated organelles and other well-established reactions to such anti-microtubule drugs. Calcium pyroantimonate (Ca-PA) deposits in most ameloblast types were markedly reduced, with the greater reduction occurring in those cells more severely altered morphologically. However, the cell membranes of both control and experimental smooth-ended maturation ameloblasts were essentially devoid of Ca-PA. The normal distribution and intensity of Ca2+,Mg2(+)-ATPase was not affected by colchicine. Because the observed reduction of membrane-associated calcium is apparently not mediated by Ca2+,Mg2(+)-ATPase in this case, other aspects of the calcium regulating system of ameloblasts are apparently targeted by colchicine.

scholarly journals Morphological changes and bioaccumulation in response to cadmium exposure in Morchella spongiola, a fungus with potential for detoxification

2021 ◽  
Author(s):  
Hongyan Xu ◽  
Jing Guo ◽  
Qing Meng ◽  
Zhanling Xie
Keyword(s):  
Electron Microscopy ◽  
Morphological Changes ◽  
Intracellular Accumulation ◽  
Tolerance Mechanism ◽  
Edible Fungi ◽  
Transmission Electron Microscopy Analysis ◽  
Transmission Electron ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Micro Morphology

<i>Morchella</i> is a genus of edible fungi with strong resistance to Cd and the ability to accumulate it in the mycelium. However, the mechanisms conferring Cd resistance in <i>Morchella</i> are unknown. In the present study, morphological and physiological responses to Cd were evaluated in the mycelia of <i>Morchella spongiola</i>. Variations in hyphal micro-morphology including twisting, folding and kinking in mycelia exposed to different Cd concentrations (0.15, 0.9, 1.5, 2.4, 5.0 mg/L) were observed using scanning electron microscopy. Deposition of Cd precipitates on cell surfaces (at Cd concentrations > 2.4 mg/L) was shown by SEM-EDS. Transmission electron microscopy analysis of cells exposed to different concentrations of Cd revealed the loss of intracellular structures and the localization of Cd depositions inside/outside the cell. FTIR analysis showed that functional groups such as C=O, -OH, -NH and -CH could be responsible for Cd binding on the cell surface of <i>M. spongiola</i>. In addition, intracellular accumulation was observed in cultures at low Cd concentrations (< 0.9 mg/L), while extracellular adsorption occurred at higher concentrations. These results provide valuable information on the Cd tolerance mechanism in <i>M. spongiola</i> and constitute a robust foundation for further studies on fungal bioremediation strategies.

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