Binding of ferritin-lectin conjugates to C-type virus in intact cells

Summary Ferritin-Ricin II and Ferritin-Concanavalin A bound to budding as well as mature C-type viral particles. No differencies in binding between the viral coat and adjacent plasma membrane were detected with either lectin conjugate. Aggregation of viral particles by lectin conjugates was observed, and linking of virus to the plasma membrane resulted in phagocytosis of viral particles.Acknowledgment. The authors thank Phyllis Johnson for her excellent technical assistance. This work was supported by NIH grant CA 15044-03 and NS 06208. LM is the recipient of an NINDS Research Career Development Award 1 KO4-NS 00101.     

Relationship between A-type and C-type particles in Ehrlich ascites tumor cells.

Intracisternal and intracytoplasmic A-type particles were discovered in Ehrlich ascites tumor cells. In addition, 'mature' and 'immature' C-type particles were also seen in the intercellular space. It is believed that A particles may represent a precursor or a formative stage of the C particles.     

Penetration of intact mitochondria by dehydroepiandrosterone and its conjugates or derivatives

Zusammenfassung Nach Bebrütung intakter Mitochondrien aus Meerschweinchenleber in 10^–4 M Lösung von 7-³H-DHEA bzw. seinen Konjugaten oder Derivaten zeigte es sich, dass lediglich lipophile Verbindungen wie das freie Steroid, besonders aber DHEA-sulfatid, durch die Membran eingedrungen und metabolisiert worden waren.     

Binding bovine immunoglobulins to anterior lobe cells of the hypophysis.

Cells of the anterior lobe of the bovine hypophysis, show an affinity for immunoglobulins IgG, IgA and IgM. The phenomenon either provides a message to stimulate cellular secretion or to excite mechanisms associated with the synthesis and release of Ig's or their determinants.     

Relationship between A-type and C-type particles in Ehrlich ascites tumor cells

Summary Intracisternal and intracytoplasmic A-type particles were discovered in Ehrlich ascites tumor cells. In addition, mature and immature C-type particles were also seen in the intercellular space. It is believed that A particles may represent a precursor or a formative stage of the C particles.Acknowledgment. The author is grateful to Professor F. P. Lisowski for his advice and helpful criticisms and to Mr Y. S. Tong for his expert technical assistance. This project was supported by a grant from the Hong Kong University Research Grants Committee.     

Binding bovine immunoglobulins to anterior lobe cells of the hypophysis

Summary Cells of the anterior lobe of the bovine hypophysis, show an affinity for immunoglobulins IgG, IgA and IgM. The phenomenon either provides a message to stimulate cellular secretion or to excite mechanisms associated with the synthesis and release of Ig's or their determinants.This study was supported by a grant from the National Research council of Canada.     

C-type virus particles in lymphocytes cultured from cows with persistant lymphocytosis. Preliminary results on French cattle stock]

C type virus particles were shown in cultures of lymphocytes originating from cows with persistent lymphocytosis. These observations on French cattle are in complete accordance with data previously obtained in the USA. Viral replication is highly stimulated by the addition of phytohemagglutinin in the culture medium. Several morphological and biological properties, specific to the bovine virus differentiate this virus from C type viruses of other species.     

Binding of matrilysin-1 to human epithelial cells promotes its activity

Matrix metalloproteinase-7 (MMP-7, matrilysin- 1) modulates crucial biological events by processing many epithelial cell surface-associated effectors. We addressed MMP-7 interaction with human epithelial cells and its resulting activity. In human endometrium, a model of controlled tissue remodeling, proMMP-7 was diffusely immunolocalized inside epithelial cells, whereas MMP-7 delineated their entire plasma membrane. Endometrial explants preferentially retained active MMP-7, but not proMMP-7. Endometrial epithelial cells and carcinoma cells from various tissues bound active MMP-7. Endometrial carcinoma-derived Ishikawa cells showed high affinity (K_D of ~2.5 nM) and capacity (~260 000 sites per cell) for MMP-7. MMP-7 binding decreased by extracting membrane sterols or interfering with heparan sulfate proteoglycans, and was abrogated by tissue inhibitors of metalloproteinase-2 (TIMP-2) or synthetic MMP inhibitors. Bound MMP-7 not only remained fully active towards a macromolecular substrate but also became resistant to TIMP-2. We conclude that MMP-7-selective targeting to the plasma membrane of epithelial cells promotes its activity by conferring resistance to TIMP-2. A. Berton, C. Selvais: These authors contributed equally to this work. P. J. Courtoy, E. Marbaix, H. Emonard: These authors contributed equally to the supervision of this work. Received 20 September 2006; received after revision 30 November 2006; accepted 18 January 2007     

Binding of D-alpha-tocopherol to rat liver nuclear components.

When D-alpha-tocopherol is administered i.v. to vitamin E deficient rats, significant amounts of this vitamin are bound to a nucleoprotein complex in hepatic nuclei, and this complex can be solubilized by high concentrations of sodium chloride (0.6 M). The bound vitamin in this complex, extractable by ethanol, was found to be identical with authentic alpha-tocopherol by thin layer chromatography.     

Binding of cytophilic rabbit IgG to homologous hepatocytes.

Rabbit liver cells were able to bind cytophilic monomeric and polymeric homologous IgG via their Fc receptor binding sites (FcR). On the other hand, non-cytophilic rabbit IgG did not bind to hepatocytes, even after its aggregation. The present findings suggest that FcR on rabbit liver cells are specific for cytophilic monomeric IgG but do not significantly bind non-cytophilic, polymeric IgG.     

Effect of influenza virus PR8 infection on thymus in intact and adrenalectomized mice

Riassunto Le alterazioni morfologiche del timo nel corso dell'infezione con virus PR8 sono più evidenti nei topi normali che nei topi adrenalectomizzati, i quali mostrano una differenziazione dei timociti in due classi sulla base dell'intensità di colorazione con bleu di toluidina.     

Induction of endogenous C-type virus by 5-iododeoxyuridine and augmentation of this induction by polycyclic hydrocarbons]

When the MLg Mouse cells were treated with the chemical carcinogens, in the presence of microsomal enzymes and NADPH2 after 5-iododeoxyuridine (IUdR) treatment, the induction frequency of the endogenous C-type virus was increased by nearly 10-fold in comparison with the cultures treated with IUdR only. In the preliminary screening of several polycyclic hydrocarbons including carcinogenic and non-carcinogenic products, apparently there was no correlation between the carcinogenecity in vivo and the stimulation capacity of IUdR induced C-type virus activation in our test conditions.     

Binding of cyanide to methemoglobin

Riassunto È stata studiata l'interazione tra metemoglobina e cianuro. Il cianuro sembra legarsi ad un solo eme e l'equilibrio non sembra influenzato da interazioni eme-eme.     

The effect of pyruvate on cyanide-inhibited respiration in intact ascites tumor cells

Riassunto È stato osservato che l'aggiunta di piruvato a cellule ascite di Ehrlich del topo è capace di rimuovere rapidamente l'inibizione della respirazione indotta da cianuro, restaurando l'integrità della fosforilazione ossidativa.     

Antigen Binding rosette forming cells in a friend virus-induced leukemia

Résumé Les souris infectées par le virus de la leucémie de Friend avaient le meme nombre de cellules spléniques capables de se lier à des érythrocytes de mouton grâc à un récepteur immunolgobuline que les souris normales, non infectées, et servant de contrôle, possédent également. De plus, les souris infectées par le virus répondent à l'immunisation par des érythrocytes de mouton defacon nettement diminuée.     

Binding of Lens culinaris lectin to sea urchin embryo chromatin.

Lentin binds specifically to sea urchin embryo chromatin. This binding is saturable and inhibited by alpha-methyl-mannose. Scatchard plot analysis of the binding reaction suggests a single binding site.