Search PubMed⌕ Search

Biomedical subjects

A Georges

Publications and source records attributed to A Georges.

At least 55 records · Page 3Linked to original sources
PubMed1995

Dilution assessment of cervicovaginal secretions obtained by vaginal washing for immunological assays.

Local immunological defense mechanisms in the cervicovaginal mucosa currently remain incompletely defined, especially from a quantitative point of view. Addition of an inert substance, lithium chloride (LiCl), into the washing buffer used to carry out the vaginal washing for collecting cervicovaginal secretions and measurement of its concentration with a flame absorption spectrophotometer, before and after the specimen is sampled, permits the quantification of the volume of cervicovaginal secretions collected and the approximation of the dilution factor of a soluble component introduced by the washing. Lithium, at a concentration of 10 mM, gives the best precision of measurement and has no effect on the results of the immunoassays. In a population of 27 nonpregnant women (age range, 18 to 45 years), the volume of cervicovaginal secretions collected by vaginal washing with 3 ml of LiCl-phosphate-buffered saline was 12% +/- 3.2% (mean +/- standard deviation) of the total volume and showed large interindividual variations (range, 5.6 to 18.8%); the mean dilution factor of a soluble component from the vaginal secretions was 9.9% +/- 2.8% (range, 6.3 to 18.8%). According to the date of the menstrual cycle, the mean volume of collected cervicovaginal secretions was significantly increased in the luteal phase in comparison with the follicular phase; conversely, the mean dilution factor of a soluble component was more important in the follicular than in the luteal phase. These features strengthen the need to quantify accurately the dilution factor introduced by vaginal washing when studying cervicovaginal immunity.

Adolescent↗
PubMed1993

Diversity of V3 region sequences of human immunodeficiency viruses type 1 from the central African Republic.

Nucleotide sequences of the central portion of gp120, including the third hypervariable (V3) loop, were obtained from lymphocytes cocultivated with SupT1 cells from 29 AIDS patients in Bangui, Central African Republic. These sequences displayed significantly greater diversity (average distance, 23%) than has been previously observed in isolates from comparably restricted geographical areas. Isolates belonging to four major subtypes of HIV-1 were found; the only subtype not represented was the North American/European subtype B. Unlike the situation in Zaire and Uganda, where subtypes A and D account equally for virtually all isolates of HIV-1, the predominant subtypes in the Central African Republic, accounting for two-thirds of the isolates, were subtypes A (10 isolates) and E (9 isolates). Subtype E represents a group of variants that have previously been found only in Thailand. Only one isolate belonging to subtype D was found. Also recovered were two isolates of subtype C, a subtype associated with southern African and Indian isolates but not previously detected in central Africa. These isolates, although clearly clustering with subtype C, formed a distinct subset, differing from one another by 8.8% and from the Indian and South African subtype C isolates by an average of 22.5%. High interpatient, intrasubtype variation was also seen among the CAR subtype A (average pairwise difference, 19.3%) and subtype E (10.9%) isolates. The diversity of V3 sequences in this set has implications for immunization protocols that rely on the recognition of V3. This study underscores the necessity of basing intervention strategies on knowledge of the particular sequences present in the target population or geographical area.

Acquired Immunodeficiency Syndrome↗
PubMed1992

[Resurgence of yaws in Central African Republic. Role of the Pygmy population as a reservoir of the virus].

The authors present the results of a clinical (framboesia) and serological (TPHA and VDRL) investigation aimed at defining the reservoir of virus of yaws in the Lobaye area (southwest of CAR) out of which the disease spreads in spite of previous mass treatment campaigns. The Lobaye focus is still active because we found among the pediatric population under the age of 15 years, 5.6% contagious skin lesion and 19.6% VDRL+. In this area with contact between nomadic Pygmies and sedentary ethnic groups, the observed level of clinical and serological attacks suggested that the pygmie population, as previously described, makes up the principal focus of yaws. For every 1 case found through clinical examination, 3.5 cases VDRL+ and 4.8 cases TPHA+ are found through serological examination. This proportion indicates that clinical screening alone is not sufficient to evaluate the endemic yaws level in a population.

Adolescent↗
PubMed1992

[Epidemiology of Tinea capitis in Bangui (Central African Republic)].

In Bangui (Central African Republic) an epidemiological survey making use of cluster sampling has been performed. Prevalence rate is not very high in Bangui (3.4%). Boys are more infected than girls. Both in rural and urban area prevalence rates are decreasing with age. Microsporum langeronii has been identified in 98% of case.

Adolescent↗