scholarly journals Differentiation of a teratocarcinoma line: preferential development of cholinergic neurons.

1981 ◽  
Vol 88 (1) ◽  
pp. 57-66 ◽  
Author(s):  
S E Pfeiffer ◽  
H Jakob ◽  
K Mikoshiba ◽  
P Dubois ◽  
J L Guenet ◽  
...  

A line of embryonal carcinoma cells, PCC7-S, established in vitro from a spontaneous testicular teratocarcinoma, has been studied. Upon removing the cells from a low density monolayer culture system and permitting the cells to form aggregates in suspension, we observed a change of several physical and biochemical parameters: (a) reduction in average cell volume, (b) blockage and accumulation of cells in G1, (c) rise in secreted protease activity, (d) rise in acetylcholinesterase and choline acetyltransferase activities, and (e) disappearance of embryonic antigen F9. Although PCC7 aggregates did not undergo substantial morphological changes while suspended, when aggregates 4 or more days old were allowed to attach to plastic tissue culture dishes, substantial neurite outgrowth occurred over the next 1-3 d. This process was markedly enhanced by the addition to the growth medium of carboxymethylcellulose and inhibitors of DNA synthesis. Transmission electron microscopy disclosed a neurite ultrastructure consistent with that of neuronal processes. A veratridine-stimulated, tetrodotoxin-blocked sodium influx of 100 nmol/min per mg protein was also observed in these differentiated surface cultures. This cell line is discussed in terms of its utility for the study of early events leading to a commitment to cellular differentiation, as well as for the investigation of terminal differentiation to cholinergic neurons.

Author(s):  
John C. Garancis ◽  
Robert O. Hussa ◽  
Michael T. Story ◽  
Donald Yorde ◽  
Roland A. Pattillo

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.


Parasitology ◽  
1981 ◽  
Vol 83 (3) ◽  
pp. 513-518 ◽  
Author(s):  
J. P. Laclette ◽  
Marie Therese Merchant ◽  
Kaethe Willms ◽  
L. Cañedo

SUMMARYThe effect of the anthelmintic Mebendazole on Cysticercus cellulosae maintained in culture medium was studied by transmission electron microscopy. In addition to the well-known morphological changes induced by Mebendazole in other cestode and nematode larvae, it also induced the cytoplasmic appearance of paracrystalline bundles in the secretory cells of the bladder wall. These bundles were formed by groups of large parallel tubules arranged in a hexagonal-like pattern. The tubules, which had an external diameter of about 50 nm and a length that might exceed 5 μm, were surrounded by a matrix and a distance between neighbouring tubules of 80–120 nm centre to centre was estimated. The tubules were stable to colchicine and low temperature. The temporary appearance of bundles is described and some alternative explanations on their origin are advanced.


1993 ◽  
Vol 84 (4) ◽  
pp. 391-399 ◽  
Author(s):  
Claus Kroegel ◽  
Ann Dewar ◽  
Tatsuo Yukawa ◽  
Per Venge ◽  
Peter J. Barnes ◽  
...  

1. Purified human eosinophils from asthmatic patients were stimulated with platelet-activating factor in vitro and examined for morphological changes by transmission electron and light microscopy. Changes were also evaluated by morphometric analysis and were related to the platelet-activating factor-stimulated release of granular eosinophil cationic protein. 2. Stimulation of eosinophils with platelet-activating factor induced a dose-dependent shape change, including the elongation of cells, loss of microvilli and the formation of lamellipodia. This effect was maximal at 25 min and was reversible. 3. Stimulation with platelet-activating factor also induced granule movement to the cell periphery and fusion of adjacent granules. Granules became swollen and vesiculated, whereas both the matrix and core showed evidence of solubilization. 4. There was a time-dependent secretion of eosinophilic cationic protein from human eosinophils upon stimulation with platelet-activating factor which occurred without significant lactate dehydrogenase release. 5. Morphometric analysis of the transmission electron micrographs indicated a significant reduction in cytoplasmic area after 10 min of incubation with platelet-activating factor from 39.0 ± 1.7 μm2 for untreated eosinophils to 33.2 ± 2.3 μm2 (P < 0.02) for platelet-activating factor-treated cells, underscoring the observation that the cells change from spherical to ellipsoidal. No significant increase in the perimeter of the cells was found. 6. The number of granule-profiles in platelet-activating factor-stimulated eosinophils was slightly reduced when compared with control, and an increase in granule area was observed 10 min after platelet-activating factor challenge (0.215 ± 0.011 μm2 versus 0.246 ± 0.016 μm2). 7. Human eosinophils from patients with asthma stimulated with platelet-activating factor undergo both cellular and granular alterations and reorganization which parallel the release of granular eosinophil basic protein.


2003 ◽  
Vol 47 (6) ◽  
pp. 1895-1901 ◽  
Author(s):  
Maria do Socorro S. Rosa ◽  
Ricardo R. Mendonça-Filho ◽  
Humberto R. Bizzo ◽  
Igor de Almeida Rodrigues ◽  
Rosangela Maria A. Soares ◽  
...  

ABSTRACT The in vitro leishmanicidal effects of a linalool-rich essential oil from the leaves of Croton cajucara against Leishmania amazonensis were investigated. Morphological changes in L. amazonensis promastigotes treated with 15 ng of essential oil per ml were observed by transmission electron microscopy; leishmanial nuclear and kinetoplast chromatin destruction, followed by cell lysis, was observed within 1 h. Pretreatment of mouse peritoneal macrophages with 15 ng of essential oil per ml reduced by 50% the interaction between these macrophages and L. amazonensis, with a concomitant increase by 220% in the level of nitric oxide production by the infected macrophages. Treatment of preinfected macrophages with 15 ng of essential oil per ml reduced by 50% the interaction between these cells and the parasites, which led to a 60% increase in the amount of nitric oxide produced by the preinfected macrophages. These results provide new perspectives on the development of drugs with activities against Leishmania, as linalool-rich essential oil is a strikingly potent leishmanicidal plant extract (50% lethal doses, 8.3 ng/ml for promastigotes and 8.7 ng/ml for amastigotes) which inhibited the growth of L. amazonensis promastigotes at very low concentrations (MIC, 85.0 pg/ml) and which presented no cytotoxic effects against mammalian cells.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Weili Xie ◽  
Qi Xie ◽  
Meishan Jin ◽  
Xiaoxiao Huang ◽  
Xiaodong Zhang ◽  
...  

Silicon carbide (SiC), a compound of silicon and carbon, with chemical formula SiC, the beta modification (β-SiC), with a zinc blende crystal structure (similar to diamond), is formed at temperature below1700∘C.β-SiC will be the most suitable ceramic material for the future hard tissue replacement, such as bone and tooth. Thein vitrocytotoxicity ofβ-SiC nanowires was investigated for the first time. Our results indicated that 100 nm long SiC nanowires could significantly induce the apoptosis in MC3T3-E1 cells, compared with 100 μm long SiC nanowires. And 100 nm long SiC nanowires increased oxidative stress in MC3T3-E1 cells, as determined by the concentrations of MDA (as a marker of lipid peroxidation) and 8-OHdG (indicator of oxidative DNA damage). Moreover, transmission electron microscopy (TEM) was performed to evaluate the morphological changes of MC3T3-E1 cells. After treatment with 100 nm long SiC nanowires, the mitochondria were swelled and disintegrated, and the production of ATP and the total oxygen uptake were also decreased significantly. Therefore,β-SiC nanowires may have limitations as medical material.


Zygote ◽  
2011 ◽  
Vol 19 (4) ◽  
pp. 297-306 ◽  
Author(s):  
M. Crocco ◽  
R.H. Alberio ◽  
L. Lauria ◽  
M.I. Mariano

SummaryCertain morphological changes at the subcellular level caused by the current techniques for in vitro embryo production seem to affect mitochondria. Many of these, including dysfunctional changes, have been associated with the presence of serum in the culture medium. Thus, the aim of the present work was to assess the mitochondrial dynamics occurring in embryos during the first 4 days of development, in order to analyze the most appropriate time for adding the serum. We used transmission electron microscopy (TEM) micrographs to calculate the embryo area occupied by the different morphological types of mitochondria, and analyzed them with Image Pro Plus analyzer. The results showed hooded mitochondria as the most representative type in 1- to 4-day-old embryos. Swollen, on-fusion, orthodox and vacuolated types were also present. When analyzed in embryos cultured without serum, the dynamics of the different mitochondrial types appeared to be similar, a fact that may provide evidence that the developmental changes control the mitochondrial dynamics, and that swollen mitochondria may not be completely inactive. In contrast, in culture medium supplemented with serum from estrous cows, we observed an increased area of hooded mitochondria by developmental day 4, a fact that may indicate an increased production of energy compared with previous days. According to these results, the bovine serum added to the culture medium seems not to be responsible for the functional changes in mitochondria.


Author(s):  
Hanne Klausen ◽  
Per Flood ◽  
John O Hjelle ◽  
Holm Holmsen

The small number of reports concerning blood platelets during deep saturation diving have shown that there may be a decrease in the number of circulating platelets. Gas bubbles are often present in theblood during decompression. In vitro, gas bubbles activate platelets, and alter the shape from discoidto spherical configuration with multiple, blunt spikes. This study was done to investigate if there are changes in the morphology of human blood platelets during deep diving. An 18 day long experimentalon-shore saturation dive to 360 msw was performed at NUTEC 1986. Bloodsamples were obtained from the 6 divers on 6 occations: pre-dive control, at 360 msw, 300 msw, 140 msw, 1 and 3 days after surfacing. Using 18 G Wasserman needles antecubital venous blood samples (3ml) were collected directly into the fixative agent (7 ml of 2% glutardialdehyde in cacodylate buffer) whilestill in the hyperbaric chamber. The samples were then decompressed,and the platelets separated from the blood by centrifugation at roomtemperature for 10 min at 190 g. Preparation to transmission electron microscopy included post-fixation in osmium tetroxide, staining uranyl-en-bloc and eventually lead, dehydration and embedding in Epon.Ultrathin sections were examined by a Philips 300 I electron microscope. The examination revealed alterations in both platelet size and shape in the course of the dive. The mean platelet area was increased during and immidiately after thedive, the greatest increase occuring at 360 msw. There was a high incidence of shape changed plateletswith spherical configuration and multiple, blunt spikes. This form was by far most abundant at 360 msw, and the morphology normalised towards surface. This rises the suspection of a pressure-related rather rhan bubble-related effect and the results indicate that plateletsin circulation can be activated bypressure itself


1991 ◽  
Vol 173 (6) ◽  
pp. 1473-1482 ◽  
Author(s):  
P Boros ◽  
J A Odin ◽  
T Muryoi ◽  
S K Masur ◽  
C Bona ◽  
...  

Anti-Fc gamma R IgM monoclonal antibodies (mAbs) isolated from lipopolysaccharide-stimulated spleen cells from tightskin (TSK) mice were found to be polyspecific, reacting with a wide variety of molecules, including double-stranded DNA, topoisomerase, RNA polymerase, and different collagen types. Approximately 60% of the polyspecific IgM mAbs have anti-Fc gamma R specificity. These anti-Fc gamma R mAbs induce the release of hydrolases from both azurophil and specific granules of human neutrophils. 25-45% of the total cellular content (determined in Nonidet P-40 lysates) of neutrophil elastase, 10-25% of beta-glucuronidase, and 30-50% of alkaline phosphatase was released after incubation with the mAbs. The degranulation process was accompanied by dramatic morphological changes shown by scanning and transmission electron microscopy. The release of hydrolytic enzymes stimulated by the IgM anti-Fc gamma R mAbs was inhibited by preincubation of neutrophils with Fab fragments of either anti-human Fc gamma RII (IV.3) or anti-human Fc gamma RIII (3G8) mAbs. The binding of the anti-Fc gamma R TSK mAbs to human neutrophils was inhibited by Fab fragments of mAb 3G8. However, we found that the TSK anti-Fc gamma R mAbs do not bind to human Fc gamma RII expressed in either CHO cells or the P388D1 mouse macrophage cell line. Since the enzyme release could be inhibited by Fab fragments of mAb IV.3, we suggest that the signal transduction may require Fc gamma RII activation subsequent to crosslinking of the glycan phosphatidyl inositol-anchored Fc gamma RIII-1. These data demonstrate for the first time that polyspecific autoantibodies with Fc gamma R specificity can trigger neutrophil enzyme release via human Fc gamma RIII-1 in vitro and indicate a possible role for such autoantibodies in autoimmune inflammatory processes.


2001 ◽  
Vol 69 (12) ◽  
pp. 7820-7831 ◽  
Author(s):  
Donna M. Bouley ◽  
Nafisa Ghori ◽  
K. Lynne Mercer ◽  
Stanley Falkow ◽  
Lalita Ramakrishnan

ABSTRACT Mycobacterium marinum causes long-term subclinical granulomatous infection in immunocompetent leopard frogs (Rana pipiens). These granulomas, organized collections of activated macrophages, share many morphological features with persistent human tuberculous infection. We examined organs of frogs with chronicM. marinum infection using transmission electron microscopy in conjunction with immunohistochemistry and acid phosphatase cytochemistry to better define the bacterium-host interplay during persistent infection. Bacteria were always found within macrophage phagosomes. These phagosomes were often fused to lysosomes, in sharp contrast to those formed during in vitro infection of J774 macrophage-like cells by M. marinum. The infected macrophages in frog granulomas showed various levels of activation, as evidenced by morphological changes, including epithelioid transformation, recent phagocytic events, phagolysosomal fusion, and disintegration of bacteria. Our results demonstrate that even long-term granulomas are dynamic environments with regard to the level of host cell activation and bacterial turnover and suggest a continuum between constantly replicating bacteria and phagocytic killing that maintains relatively constant bacterial numbers despite an established immune response. Infection with a mutant bacterial strain with a reduced capacity for intracellular replication shifted the balance, leading to a greatly reduced bacterial burden and inflammatory foci that differed from typical granulomas.


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