scholarly journals Characterization of human heterophil hemolysins induced by Schistosoma mansoni infection

1983 ◽  
Vol 78 (3) ◽  
pp. 257-267 ◽  
Author(s):  
Munir Chamone ◽  
L. Alves Oliveira ◽  
P. M. Z. Coelho ◽  
G. Gazzinelli ◽  
A. Oliveira Lima ◽  
...  

Heterophil antibodies could be detected in sera from normal or from patient with chronic schistosomiasis. Their hemolytic activities depend on the integrity of the complement classic pathway. The heterophil antibodies from patient sera presented a higher specificity for Schistosoma mansoni antigen preparations than those detected in normal sera. Most of the hemolytic activity observed in normal sera can be destroyed at 56ºC for 4 min. On the other hand, about 80% of the sera from infected patients are partially or totally resistant to this heat-treatment. The hemolytic activities of sera were eluted from a gel filtration column in different fractions of the first peak.

1982 ◽  
Vol 47 (03) ◽  
pp. 197-202 ◽  
Author(s):  
Kurt Huber ◽  
Johannes Kirchheimer ◽  
Bernd R Binder

SummaryUrokinase (UK) could be purified to apparent homogeneity starting from crude urine by sequential adsorption and elution of the enzyme to gelatine-Sepharose and agmatine-Sepharose followed by gel filtration on Sephadex G-150. The purified product exhibited characteristics of the high molecular weight urokinase (HMW-UK) but did contain two distinct entities, one of which exhibited a two chain structure as reported for the HMW-UK while the other one exhibited an apparent single chain structure. The purification described is rapid and simple and results in an enzyme with probably no major alterations. Yields are high enough to obtain purified enzymes for characterization of UK from individual donors.


1988 ◽  
Vol 254 (2) ◽  
pp. 419-426 ◽  
Author(s):  
P M Wiest ◽  
E J Tisdale ◽  
W L Roberts ◽  
T L Rosenberry ◽  
A A F Mahmoud ◽  
...  

Biosynthetic labelling experiments with cercariae and schistosomula of the multicellular parasitic trematode Schistosoma mansoni were performed to determine whether [3H]palmitate or [3H]ethanolamine was incorporated into proteins. Parasites incorporated [3H]palmitate into numerous proteins, as judged by SDS/polyacrylamide-gel electrophoresis and fluorography. The radiolabel was resistant to extraction with chloroform, but sensitive to alkaline hydrolysis, indicating the presence of an ester bond. Further investigation of the major 22 kDa [3H]palmitate-labelled species showed that the label could be recovered in a Pronase fragment which bound detergent and had an apparent molecular mass of 1200 Da as determined by gel filtration on Sephadex LH-20. Schistosomula incubated with [3H]ethanolamine for up to 24 h incorporated this precursor into several proteins; labelled Pronase fragments recovered from the three most intensely labelled proteins were hydrophilic and had a molecular mass of approx. 200 Da. Furthermore, reductive methylation of such fragments showed that the [3H]ethanolamine bears a free amino group, indicating the lack of an amide linkage. We also evaluated the effect of phosphatidylinositol-specific phospholipase C from Staphylococcus aureus: [3H]palmitate-labelled proteins of schistosomula and surface-iodinated proteins were resistant to hydrolysis with this enzyme. In conclusion, [3H]palmitate and [3H]ethanolamine are incorporated into distinct proteins of cercariae and schistosomula which do not bear glycophospholipid anchors. The [3H]ethanolamine-labelled proteins represent a novel variety of protein modification.


1982 ◽  
Vol 25 (4) ◽  
pp. 487-490
Author(s):  
Gerd Rodé

AbstractThis paper gives a new characterization of the dimension of a normal Hausdorff space, which joins together the Eilenberg-Otto characterization and the characterization by finite coverings. The link is furnished by the notion of a system of faces of a certain type (N1,..., NK), where N1,..., NK, K are natural numbers. It is shown that a space X contains a system of faces of type (N1,..., NK) if and only if dim(X) ≥ N1 + … + NK. The two limit cases of the theorem, namely Nk = 1 for 1 ≤ k ≤ K on the one hand, and K = 1 on the other hand, give the two known results mentioned above.


1997 ◽  
Vol 39 (3) ◽  
pp. 159-164 ◽  
Author(s):  
Christiane Finardi PANCERA ◽  
Adriana Leal ALVES ◽  
Maria Aparecida PASCHOALOTTI ◽  
Pedro Paulo CHIEFFI

Mebendazole, albendazole, levamisole and thiabendazole are well known as active drugs against several nematode species, and against cestodes as well, when the first two drugs are considered. None of the drugs have proven activity, however, against trematodes. We tested the effect of these drugs on the fecal shedding of schistosome eggs and the recovering of adult schistosomes, after portal perfusion in Schistosoma mansoni experimentally infected mice. Balb/c mice infected with 80 S. mansoni cercariae were divided into three groups, each in turn subdivided into four other groups, for each tested drug. The first group was treated with each one of the studied drugs 25 days after S. mansoni infection; the second group was submitted to treatment with each one of the drugs 60 days after infection. Finally, the third group, considered as control, received no treatment. No effect upon fecal shedding of S. mansoni eggs and recovering of schistosomes after portal perfusion was observed when mice were treated with either mebendazole or albendazole. Mice treated with either levamisole or thiabendazole, on the other hand, showed a significant reduction in the recovering of adult schistosomes after portal perfusion, mainly when both drugs were given during the schistosomula evolution period, i.e., 25 days after cercariae penetration, probably due to unspecific immunomodulation


2015 ◽  
Vol 10 (1) ◽  
pp. 1934578X1501000
Author(s):  
Amadeo Gironés-Vilaplana ◽  
Diego A. Moreno ◽  
Cristina García-Viguera

“Pacharán” is an aniseed liquor-based beverage made with sloe berry ( Prunus spinosa L.) that has been produced in northern Spain. On the other hand, maqui berry ( Aristotelia chilensis) is a common edible berry from Chile, and currently under study because of its multiple beneficial effects on health. The aim of this work was to design a new aniseed liquor-based beverage with maqui berry, as an industrial alternative to a traditional alcoholic product with bioactive berries. The characterization of its composition, compared with the traditional “Pacharán”, and its evolution during maceration (6 and 12 months) showed that the new maqui liquor had significantly-higher anthocyanin retention over time. More studies on the organoleptic properties and bioactivity are underway.


2020 ◽  
Vol 2 (1-2) ◽  
pp. 181-191 ◽  
Author(s):  
Giancarlo Guizzardi

According to the FAIR guiding principles, one of the central attributes for maximizing the added value of information artifacts is interoperability. In this paper, I discuss the importance, and propose a characterization of the notion of Semantic Interoperability. Moreover, I show that a direct consequence of this view is that Semantic Interoperability cannot be achieved without the support of, on one hand, (i) ontologies, as meaning contracts capturing the conceptualizations represented in information artifacts and, on the other hand, of (ii) Ontology, as a discipline proposing formal meth- ods and theories for clarifying these conceptualizations and articulating their representations. In particular, I discuss the fundamental role of formal ontological theories (in the latter sense) to properly ground the construction of representation languages, as well as methodological and computational tools for supporting the engineering of ontologies (in the former sense) in the context of FAIR.


1924 ◽  
Vol 39 (5) ◽  
pp. 745-755 ◽  
Author(s):  
Oswald T. Avery ◽  
James M. Neill

In the present work on oxidation and reduction by sterile extracts of pneumococcus, the preparations employed contain among other constituents, a hemolytic substance the properties of which have been described by Cole (1, 2) in his studies on pneumococcus hemotoxin. Pneumococcus extracts prepared by the methods described are actively hemolytic, 0.005 cc. of extract causing complete lysis of 2.5 cc. of a 1 per cent suspension of red cells from rabbit blood. This hemolytic property of pneumococcus extracts is destroyed by 10 minutes exposure to 55°C. When pneumotoxin-containing extracts are protected from the action of molecular oxygen, their hemolytic activity remains unimpaired for considerable periods of time. In the presence of air, on the other hand, the stability of the hemolytic substance depends upon whether the particular type of extract contains a "complete" or "incomplete" oxidation-reduction system. Sterile broth extracts of unwashed pneumococci are reactive with molecular oxygen, and as a result of this union peroxide is formed whenever these extracts are exposed to air. The hemolytic activity of "complete" extracts of this type is rapidly decreased and finally destroyed in the presence of molecular oxygen. On the other hand, the "incomplete" type of extract prepared by saline extraction of washed pneumococci may be exposed to air with little or no loss of hemolytic power. This "incomplete" washed cell extract, unless reactivated, does not undergo autoxidation in the presence of air; under these circumstances peroxide is not formed and the hemolytic activity of this type of extract is not impaired by exposure to air. The stability of the hemolytic agent in the "incomplete" type of extract is evidence that this substance is itself not reactive with or affected by molecular oxygen, even in the presence of the cell enzymes. The destruction of the same hemolytic substance in extracts capable of undergoing autoxidation may be ascribed to the action of some peroxide formed by the union of molecular oxygen with easily oxidized or autoxidizable substances of the extract. It is now known that a peroxide, having the reactions of hydrogen peroxide, accumulates in sterile pneumococcus extracts during oxidation. It has been shown in the present study that the addition of preformed hydrogen peroxide destroys the hemolytic activity of pneumococcus extracts, although higher concentrations were required than were detected in oxidized extracts themselves. These facts and the known action of superoxides in analogous types of reaction make it seem not unlikely that the active agent in the destruction of pneumotoxin in oxidized cell extracts may be a peroxide; either hydrogen peroxide or some higher organic peroxide formed during autoxidation of the extract.


2007 ◽  
Vol 09 (04) ◽  
pp. 473-513 ◽  
Author(s):  
DAVID CHIRON

The purpose of this paper is to relate two notions of Sobolev and BV spaces into metric spaces, due to Korevaar and Schoen on the one hand, and Jost on the other hand. We prove that these two notions coincide and define the same p-energies. We review also other definitions, due to Ambrosio (for BV maps into metric spaces), Reshetnyak and finally to the notion of Newtonian–Sobolev spaces. These last approaches define the same Sobolev (or BV) spaces, but with a different energy, which does not extend the standard Dirichlet energy. We also prove a characterization of Sobolev spaces in the spirit of Bourgain, Brezis and Mironescu in terms of "limit" of the space Ws,p as s → 1, 0 < s < 1, and finally following the approach proposed by Nguyen. We also establish the [Formula: see text] regularity of traces of maps in Ws,p (0 < s ≤ 1 < sp).


1985 ◽  
Vol 1 (1) ◽  
pp. 69-81 ◽  
Author(s):  
Robert J. van der Veen ◽  
Philippe Van Parijs

In Anarchy, State, and Utopia, Robert Nozick contrasts entitlement theories of justice and “traditional” theories such as Rawls', utilitarianism or egalitarianism, and advocates the former against the latter. What exactly is an entitlement theory (or conception or principle) of justice? Nozick's book offers two distinct characterizations. On the one hand, he explicitly describes “the general outlines of the entitlement theory” as maintaining “that the holdings of a person are just if he is entitled to them by the principles of justice in acquisition and transfer, or by the principle of rectification of injustice (as specified by the first two principles of just acquisition and transfer)” (Nozick, 1974, p. 153). On the other hand, his famous “Wilt Chamberlain” argument against alternative theories is first said to apply to (all) “non-entitlement conceptions” (p. 160), and later to any “end-state principle or distributional patterned principle of justice” (p. 163) — which amounts to an implicit characterization of an entitlement conception (theory, principle) as a conception of justice which is neither end-state nor patterned.


1971 ◽  
Vol 28 (6) ◽  
pp. 879-882 ◽  
Author(s):  
M. John Chapman ◽  
Christopher Chin ◽  
Finn Wold

Enolase has been isolated from lobster muscle by acetone fractionation, heat treatment, ammonium sulfate fractionation, gel filtration, and ion-exchange chromatography. Preliminary characterization of the pure enzyme shows that the catalytic properties are very similar to those of the enolases from rabbit and fish.


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