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Biomedical subjects

A Aceti

Publications and source records attributed to A Aceti.

At least 37 records · Page 2Linked to original sources
PubMed1993

IgG subclasses in human hydatid disease: prominence of the IgG4 response.

To assess the participation of the four subclasses of IgG in the humoral response to Echinococcus granulosus infection, we determined total and parasite-specific IgG1, IgG2, IgG3 and IgG4 in sera from 46 patients with hydatid disease using an enzyme-linked immunosorbent assay (ELISA). Parasite-specific IgG subclass antibodies were quantitatively measured by means of standard curves obtained by affinity chromatography. Sera from 35 healthy individuals served as controls. The total component of IgG1, IgG2, and IgG3 showed a slight increase in patients with hydatidosis in comparison to normal control subjects with no significant differences. For the IgG4 subclass, however, a marked elevation was found in the patients group (p = 0.001 by analysis of variance). IgG1 and IgG4 subclasses showed a high anti-echinococcus antibody response, whereas there was a low parasite-specific IgG2 and IgG3 response. Indeed IgG-specific antibodies were found to belong mainly to IgG1 (63%) and to IgG4 (30%) and to a lesser extent to IgG2 (5%) and IgG3 (2%). The percentage of the total serum IgG4 antibodies that were specific for hydatid antigen reached a mean level of 18%, significantly higher than that of any of the other three IgG subclasses (p < 0.001 by Student's t test). Thus, the continuous antigenic stimulation of hydatidosis may result in an enhanced IgG4 subclass response.

Adult↗
PubMed1993

Hepatitis C virus infection in chronic liver disease in Somalia.

To assess the role of hepatitis C virus (HCV) in liver disease in Somalia, antibody to HCV (anti-HCV) was studied by enzyme-linked immunosorbent assay (ELISA) and recombinant immunoblot assay (RIBA) in 110 patients with chronic liver diseases, in 309 healthy adults, in 179 institutionalized subjects with a high prevalence of intestinal parasites and Schistosoma haematobium, and in 287 children with diseases other than hepatitis. According to the RIBA test, anti-HCV was present in three healthy adults (0.97%), in four institutionalized individuals (2.2%), but in none of the children. The prevalence of anti-HCV was 4.8% in patients with hepatitis B surface antigen (HBsAg)-positive chronic liver diseases and 20.6% in patients with HBsAg-negative chronic liver diseases. Thus, HCV infection appears to play a minor role in HBsAg-positive liver disease in Somalia but may be an important factor in HBsAg-negative chronic liver disease. The low anti-HCV prevalence in individuals with no hepatic disorders is consistent with the fact that HCV does not spread by nonpercutaneous transfer. We found also a large proportion of both patients with hepatic disease and institutionalized individuals who tested positive by ELISA but not confirmed by RIBA. However, the likelihood of a true positive result increases proportionally with the ELISA value; thus, in most cases a low ELISA value probably represents a false-positive reaction, while a high ELISA value probably represents a true positive reaction.

Adult↗
PubMed1992

Spontaneous in vitro generation of histamine releasing factor from mononuclear cells of patients with hydatidosis.

We have shown that Echinococcus granulosus infection can induce an enhanced sensitivity of basophils to IgE-dependent stimuli. To determine whether a cytokine, histamine releasing factor, could account for it, we evaluated 35 patients with active hydatidosis, 5 patients with past E. granulosus infection, and 20 normal volunteers. The spontaneous production of a factor in vitro that provoked the release of histamine from basophils was observed by mononuclear cells from patients with active disease, but not by those from subjects with past infection or from normal individuals. The histamine releasing factor was found to activate basophils through surface-bound IgE. It is concluded that E. granulosus infection induces both generation of histamine releasing factor and production of IgE that can bind this cytokine.

Basophils↗
PubMed1992

The association of Helicobacter pylori infection with low levels of urea and pH in the gastric juices.

Fifty-four gastric biopsies and their relative gastric juices were analyzed for the presence of Helicobacter pylori with both cultural and microscopic methods. Thirty-one samples were positive and twenty-three were negative. These data were therefore employed as references for the subsequent comparisons. Furthermore, the gastric juices were later tested to establish the urea concentration and the pH level. In addition, the sediment obtained after centrifugation was microscopically observed for the possible presence of other bacterial flora in the sample (unstained smears). The urease test on the bioptic specimens has also been evaluated. The presence of H pylori was strictly related to urea levels of less than 15 mg/dl and pH less than 3.5. Furthermore, H pylori was generally not associated with the presence of other bacterial flora (only 1 out of 12 samples). The latter instead, was almost exclusively present in high pH samples (with the exception of one). On the basis of these results, a simple diagnostic scheme was constructed to identify carrier subjects. All patients (14/14) with urea levels of more than 15 mg/dl were found to be negative as well as those presenting a pH of more than 3.5 (7/9) or evidence of other bacteria in the juices (8/9). The remaining subjects (30/31 or 29/31, respectively) presented H pylori in the gastric juices. The final classification was 96.3% (or 94.4%) correct.

Female↗
PubMed1991

Basophil-bound and serum immunoglobulin E directed against Helicobacter pylori in patients with chronic gastritis.

The immunoglobulin (Ig) E immune response in patients with Helicobacter pylori-associated chronic gastritis has been evaluated. Of 26 patients with H. pylori infection, 22 (84%) tested positive for basophil-bound specific IgE (determined by the histamine release test) and 18 (69%) for serum specific IgE (determined by an enzyme-linked immunosorbent assay). In contrast, only 1 of 17 persons in whom the bacterium was not detected presented cell-bound and serum specific IgE. In the 4 histamine release test--positive but enzyme-linked immunosorbent assay--negative patients, removal of antibody from the basophil surface by acid elution showed that histamine release occurred through an IgE-dependent mechanism. When normal basophils, passively sensitized with serum from IgE-positive patients, were exposed to the H. pylori antigen, a significant release was observed, confirming the class specificity of the response. Inhibition experiments with bacteria other than H. pylori showed that the IgE antibody was specifically directed against this organism. The percentage of antigen-induced histamine release did not correlate with serum specific IgE level. However, the response of basophils to antigenic challenge was proportional to IgE-dependent cellular releasability. This finding suggests that target cell sensitivity may be the most important factor in determining the entity of biological response to the antigenic challenge. The ability of H. pylori to induce a specific IgE immune response could answer key questions regarding the mechanisms inducing gastric inflammation.

Chronic Disease↗
PubMed1991

The serological diagnosis of human hydatid disease by time-resolved fluoroimmunoassay.

The use of a new immunoassay, time-resolved fluoroimmunoassay (TR-FIA), in the diagnosis of human hydatid disease has been evaluated. This technique, which is based on the labelling of antibodies with europium (Eu), was compared with a well-established method, the enzyme linked immunosorbent assay (ELISA). Of 102 patients with hydatid disease, 97 (95.1%) were positive according to TR-FIA and 83 (81.4%) according to ELISA. The rate of non-specificity for other parasitic infections (n = 206) was 8.7% for TR-FIA and 17.5% for ELISA. It is concluded that TR-FIA is more sensitive and more specific than ELISA in the diagnosis of human hydatid disease.

Animals↗