Biomedical subjects

G Zamacona

Publications and source records attributed to G Zamacona.

At least 19 recordsLinked to original sources

PubMed1978

[Activity of the alternative complement pathway by various axenic strains of Entamoeba histolytica].

The activation of the alternative pathway of complement by axenic cultures of E. histolytica is reported. The activation is carried out in different proportions by several axenic strains, i.e., HK9:NIH, HM1:IMSS, HM2:IMSS and HM3:IMSS; the end result consists of a destruction of the parasite as well as consumption of the serum complement. The participation of the alternative pathway was studied in the presence of EGTA and Mg++, zymosan, heat-inactivation at 50 degree C for 20 min and immunoelectrophoretic studied with anti-factor B.

Animals↗

PubMed1978

[A new hemagglutination method to determine antibodies against Entamoeba histolytica].

A passive hemagglutination method useful for the determination of antibodies against Entamoeba histolytica is described. The E. histolytica antigen is attached to group "O" human red blood cells by means of CrCl3. The specificity and sensitivity of the CrCl3 method was compared with other hemagglutination methods, i.e., tannic acid method and a commercial preparation, as well as counterimmunoelectrophoresis. The CrCl3 method showed a reactivity similar to the tannic acid hemagglutination technique and greater specificity than the commercial preparation. The assay reported here showed a good correlation with the counterimmunoelectrophoresis method. The sensitization of erythrocytes with the amebic antigen by means of CrCl3 offers an easy, rapid and specific technique which can be used as a routine test for the detection of antibodies against E. histolytica.

Amebiasis↗

PubMed1978

Activation of the alternative pathway of complement by Entamoeba histolytica.

A cytopathogenic effect was observed when Entamoeba histolytica was exposed to human sera from individuals with no clinical history or laboratory evidence of amoebiasis. Absorption studies showed that the effect was not due to natural antibodies. Studies performed using ethylenediamine tetracetic acid (EDTA), cobra venom factor (CoF) and heat-inactivation at 56 degrees C, indicated that the cytopathogenic effect was complement dependent. Furthermore, by using ethylene glycol tetracetic acid (EGTA) and Mg++, zymosan, heat-inactivation at 50 degrees C to destroy the activity of factor B of the alternative pathway, as well as electrophoretic studies with anti-human factor B, it was possible to determine that E. histolytica activated the properdin pathway. Finally, complement determinations indicated that incubation of E. histolytica with normal human serum consumed complement. The diminution in CH50 correlated with a consumption of C3 but not of C1, C4 and C2. It was concluded from these results that trophozoites of E. histolytica activate the alternative pathway of the human complement system.

Animals↗

PubMed1978

[Description of a method for measuring sera with a high level fo IgE: test through the inactivation of anti-IgE covered phages].

The Fab fragment of an anti-IgE serum was conjugated with the bacteriophage T4 through the use of glutaraldehyde. The conjugated phage was inactivated by human sera which contained IgE. The degree of inactivation allowed to make a distinction between the sera of normal individuals and that of those in whom it is known that high levels of Ig E exist, as in patients with allergic diseases. The method is quite sensitive, economical and does not require costly equipment. Besides, the conjugated phage is preserved for prolonged periods of time.

Coliphages↗

PubMed1978

[Determination of the alternative complement pathway in patients with amebic liver abscess].

The activation of the alternative pathway of complement in the sera of patients with amebic liver abscess was studied. Of 11 sera examined, only six showed an activation of the alternative pathway. However, all sera showed diminished levels of complement (CH50) and C3, in spite of normal levels of C1q. The results suggest that the sera of patients with invasive amebiasis have a substance capable of activating the properdin pathway. The significance of these observations is not completely clear at the present time.

Complement Activation↗

PubMed1975