Search PubMed⌕ Search

Biomedical subjects

G Richer

Publications and source records attributed to G Richer.

63 records · Page 4Linked to original sources
PubMedDate not supplied

Evaluation of variables in immunofluorescence procedures for the detection of antibodies against human herpesvirus 6 (HHV-6).

Ten human sera were used to study different parameters, namely, methods of smear preparation and fixation, and age of infected HSB-2 cells in order to optimize indirect immunofluorescence assay (IFA) and anticomplement immunofluorescence (ACIF) procedures to measure antibody levels against HHV-6. Results showed a greater sensitivity of rapid smear drying and methanol fixation over conventional acetone smear preparation. Cells harvested 6 days after infection and fixed with methanol exhibited a sharper and more intense fluorescence. IFA titers were higher than those obtained with ACIF, although the latter procedure enabled the distinction between three fluorescent sites. Reactivity pattern of individual sera against infected cells was variable and indicated that the human immune response to HHV-6 is directed against different antigens. An easier interpretation and a better definition of the fluorescence of HSB-2 cell line infected with HHV-6 strain Dv is obtained with the following conditions: cells should be harvested at 5-8 days after infection (at the giant cell stage of infection), cell smears have to be dried quickly before fixation with methanol at -20 degrees C, and finally, they should be stained by IFA.

Acetone↗
PubMedDate not supplied

[Diagnosis of genital Chlamydia trachomatis infections using antigen detection and cell culture].

The purpose of this study is: 1. comparing the immuno-enzymatic method (E.L.I.S.A. Abbott) and the cellular culture in the screening of the chlamydial genital infections; 2. evaluating these two tests in post-treatment control. During a 3 month period, 825 patients of our S.T.D. Clinic are considered a risk group and 144 have a positive culture. The E.L.I.S.A. method presents a sensitivity of 70.8% and a specificity of 98.5%. On the other hand, the sensitivity rises up to 80.9% if we retain only the primary culture. Interesting fact: if the reading on the spectrophotometer (E.L.I.S.A. Quantum) is greater than 0.7, the culture is always positive. Being a sexual contact of an infected person, having more than one partner or an history of a S.T.D. in the past, all these factors increase the risk of a chlamydial positivity, but in female only. We observe that 76.5% of patients suffering from gonorrhea have also a chlamydial infection proven by culture. Following a post-treatment control of one week, 5 cases remain positive, that is 3 by E.L.I.S.A. and 2 by culture, while three weeks later all cases are negative. The E.L.I.S.A. method has a good correlation with culture, is highly specific and the reading of optic density seems useful in predicting a positive culture. Risk factors are not the same in male and female. The post-treatment controls by both methods are not always similar if they are performed after one or three weeks.

Adult↗