Search results for "guinea"
showing 10 items of 412 documents
Opsonizing activities of IgG, IgM antibodies and the C3b inactivator-cleaved third component of complement in macrophage phagocytosis
1976
Phagocytosis of SRBC by guinea-pig peritoneal macrophages is enhanced by opsonizing IgG antibody alone. IgM antibody requires the presence of bound C3. Treatment of C3b coated SRBC with purified C3b inactivator (yielding EAIgM C1423d) does not reduce attachment to, and phagocytosis by, peritoneal macrophages. This finding suggests the existence of a C3d receptor on peritoneal macrophages. EC43b intermediates which have been produced by removing IgM antibody by mercaptoethanol treatment and by subsequent removal of C1 and C2, are phagocytosed despite the absence of IgM antibody. Furthermore, treatment of EC43b with C3b inactivator does not change phagocytosis. Thus, IgM antibody does not app…
Quantitative studies of the secretion of complement component C3 by resident, elicited and activated macrophages. Comparison with C2, C4 and lysosoma…
1982
To quantitate the secretion of complement component C3 by guinea pig peritoneal macrophages an enzyme-linked immunosorbent assay was developed. C3 secretion was studied in resident, elicited and activated macrophages and compared with release of hemolytically active C2 and C4, as well as the lysosomal enzyme β-D-2-acetamido-2-deoxyglucosidase. Resident macrophages secreted about 6 ng C3/106 cells/h into culture supernatants over a period of 12 h. Corynebacterium parvum-activated cells were found to secrete 3 times that amount at nearly constant rates. There was a stepwise increase in secretion of functional C2 and C4 when comparing resident, elicited and activated macrophages; secretion was…
Transformation of the dermatophyte Trichophyton mentagrophytes to hygromycin B resistance.
1989
A transformation system for the ringworm-producing dermatophyte Trichophyton mentagrophytes has been developed. The system employs the plasmid pHIS, which contains a bacterial hygromycin B phosphotransferase gene linked to Cochliobolus heterostrophus regulatory sequences (B. G. Turgeon, R. C. Garber, and O. C. Yoder, Mol. Cell. Biol. 7:3297-3305, 1987). This plasmid confers hygromycin B resistance to T. mentagrophytes. The DNA was stably integrated into the fungal genome, and the number and sites of integrations varied among transformants. Transformant clones were capable of infecting guinea pigs. This system opens the way for the molecular genetic analysis of the interaction of T. mentagro…
MRI using hyperpolarized noble gases.
1998
The aim of this study was to review the physical basis of MRI using hyperpolarized noble gases as well as the present status of preclinical and clinical applications. Non-radioactive noble gases with a nuclear spin 1/2 (He-3, Xe-129) can be hyperpolarized by optical pumping. Polarization is transferred from circularly polarized laser light to the noble-gas atoms via alkali-metal vapors (spin exchange) or metastable atoms (metastability exchange). Hyperpolarization results in a non-equilibrium polarization five orders of magnitude higher than the Boltzmann equilibrium compensating for the several 1000 times lower density of noble gases as compared with liquid state hydrogen concentrations in…
Independencia y descolonización de Guinea Ecuatorial
2018
Fue en el año 1777 cuando España y Portugal firmaron en San Ildefonso el Tratado Preliminar de Límites en América Meridional. Portugal cedió a España sus islas Fernando Poo y Annobón, así como el territorio continental lo que después sería Río Muni. A cambio se entregaron la isla Santa Catalina y la Colonia de Sacramento a Portugal. Un año más tarde se hizo la ratificación en el Pardo el 11 de marzo, constituyendo el título jurídico de la presencia española en el Golfo de Guinea. Iniciaba así su “aventura africana”. No fue realmente hasta principios del siglo XX, con la pérdida de Cuba en 1898, que España manifestó su poder en los territorios del Golfo de Guinea. Tras aproximadamente 50 año…
Guinea Worm Disease: A Neglected Diseases on the Verge of Eradication
2022
Background: Dracunculiasis, also known as Guinea worm disease (GWD), is a neglected tropical disease (NTD) caused by a parasite (Dracunculus medinensis). In the past, dracunculiasis was known as “the disease of the empty granary” because of the difficulties patients had in going to work in fields or to school when affected by this disease. In tropical areas, the condition has been widespread in economically disadvantaged communities, and has been associated with reduced economic status and low levels of education. Methods: we searched PubMed, Scopus, Google Scholar, EMBASE, Cochrane Library, and WHO websites for literature addressing dracunculiasis published in the last 50 years. Results: b…
5-Oxo-1,4-dihydroindenopyridines: Calcium modulators with partial calcium agonistic activity
1990
The title compounds 4a-g were prepared by Knoevenagel reactions of 1,3-indandione (1) with the aromatic aldehydes 2a-g followed by cyclizing Michael addition of the products thus obtained with methyl β-aminocrotonate (3). The structures of products 4 were characterized by spectal data. Positive inotropic activities were observed on electrically stimulated, left atria of giunea pigs and these effects could be attributed to calcium agonism. On the other hand, barium chloride-induced contractions of guinea pig ileum were inhibited in a dose-dependent manner.
Über den Einfluß von Mn++-Ionen auf die positiv inotrope Wirkung einiger Pharmaka an isolierten Meerschweinchenvorhöfen / The Influence of Mn++-Ions …
1969
An isolierten linken Vorhofen von Meerschweinchen wurde der Einflus von Mn++ -Ionen auf die positiv inotrope Wirkung von Adrenalin, Theophyllin und Digitoxigenin bei verschiedenen extracellularen Calciumkonzentrationen ([Ca2+ e ; 0, 45–7, 2 mMol/l) untersucht. Die Praparate wurden elektrisch gereizt (Frequenz 3 Hz), die Spannungsentwicklung isometrisch uber Dehnungsstreifen auf Direktschreibern registriert. Die fur die Versuche verwendete Tyrodelosung enthielt keinen Phosphatpuffer, um ein Ausfallen von Mn++ zu verhindern. — Mn++ (0, 1 bis 50 mM) wirkte dosisabhangig negativ inotrop. Die Wirkung von Mn++ setzte sofort nach Zugabe ein. Sie war voll reversibel und nahm mit steigender [Ca2+ e …
ChemInform Abstract: 5-Oxo-1,4-dihydroindenopyridines: Calcium Modulators with Partial Calcium Agonistic Activity.
1990
The title compounds 4a-g were prepared by Knoevenagel reactions of 1,3-indandione (1) with the aromatic aldehydes 2a-g followed by cyclizing Michael addition of the products thus obtained with methyl β-aminocrotonate (3). The structures of products 4 were characterized by spectal data. Positive inotropic activities were observed on electrically stimulated, left atria of giunea pigs and these effects could be attributed to calcium agonism. On the other hand, barium chloride-induced contractions of guinea pig ileum were inhibited in a dose-dependent manner.
Opposite effects of beta-adrenoceptor stimulation and 8-bromo-cyclic AMP on potassium efflux in mammalian heart muscle.
1980
beta-adrenoceptor stimulation by isoprenaline increases the potassium efflux in beating guinea-pig atria. This effect is not mimicked by 8-bromo-cyclic AMP, a cyclic AMP analogue which exerts a positive inotropic effect in this preparation.