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Biomedical subjects

S Dunan

Publications and source records attributed to S Dunan.

At least 19 recordsLinked to original sources

Western blot analysis of antibodies to Leishmania infantum antigens: potential of the 14-kD and 16-kD antigens for diagnosis and epidemiologic purposes.

When infected with Leishmania species, patients develop specific antibodies that constitute the basis of serodiagnosis. Using Western blot analysis, we studied the specificity of anti-L. infantum antibodies in patients with visceral leishmaniasis (including patients with acquired immunodeficiency syndrome [AIDS]) and in healthy subjects living in an endemic area. Sera from patients with visceral leishmaniasis recognized numerous antigens that had a molecular mass range of 12-120 kD. The 14-, 16-, 28-30-, 46-, and 68-kD antigens were recognized by 92%, 95%, 63%, 80%, 69%, and 89% of the patients' sera, respectively. The 14-16-kD antigens had the greatest specificity for leishmaniasis. The same pattern was found with sera from AIDS patients with proven leishmaniasis, but the 14-kD band was not present in some cases; recognition of the 16-kD band was constant. In these patients, Western blotting characterized specific antibodies even when the results of classic serologic tests (indirect immunofluorescent antibody test and enzyme-linked immunosorbent assay) were negative. Western blotting was found to be more sensitive than the IFA and ELISA, and it was used to detect antibodies to the 14-, 16-, 22-, and 24-kD antigens in subjects living in an endemic area. The detection of antibodies for the 14-kD and 16-kD Leishmania antigens would be a valuable tool both in the diagnosis of visceral leishmaniasis and in epidemiologic studies.

Acquired Immunodeficiency Syndrome

Evidence of subjects sensitized to Leishmania infantum on the French Mediterranean coast: differences in gamma interferon production between this population and visceral leishmaniasis patients.

The Marseilles region is an endemic area for visceral mediterranean leishmaniasis, but although the number of dog cases, the parasite's main host, is very high, only a few people develop the disease. We looked for sensitized healthy subjects among 25 healthy individuals living in this area by studying their in vitro lymphoproliferative response to Leishmania infantum antigens and gamma interferon synthesis. We found that 65% of tested subjects were sensitized against L. infantum. We compared their cell mediated immunity to that of 13 active Kala-Azar patients and 13 controls from non-endemic areas. In patients, results showed a specific cellular immuno-deficiency in the lymphocyte response to L. infantum antigens and a global deficiency of gamma interferon production. Interestingly, the healthy individuals from the endemic area who responded to L. infantum antigens were found to produce high gamma interferon levels after L. infantum antigen stimulation. After healing, the cell mediated-immunity of the 3 patients we followed up was similar to that of the sensitized tested healthy subjects, but the former were still producing antibodies at the time of study.

Adolescent

[Study of cellular immunity in patients with Mediterranean visceral leishmaniasis].

Cellular immunity against Leishmania infantum antigens was studied in visceral leishmaniasis patients and healthy subjects living in a endemic area. Only the healthy subjects were TTL positive with production of gamma interferon, whereas the visceral leishmaniasis patients presented a transitory inhibition of their specific cellular response mechanisms.

Adult

Vaccination trial against canine visceral leishmaniasis. Phocean Veterinary Study Group on Visceral Leishmaniasis.

In a double-blind study 393 seronegative dogs, residing in a holoendemic area for Leishmania donovani infantum infection, were randomly assigned to an immunization with a partly purified L.d. infantum-derived preparation, or received adjuvant only. During the first year of the study period the rate of infection was significantly higher in the vaccinated group than in the control one (P less than 0.05), but this difference disappeared during the second year (P = 0.44). Since a similar immunization protocol conferred resistance against experimental murine leishmaniasis, these results stress the differences that may exist between the natural hosts of Leishmania parasites and experimental animal substitutes.

Animals

Mediterranean spotted fever in the South of France; serosurvey of dogs.

The authors tested 481 dog sera from the South of France for Rickettsia conorii antibodies using an Indirect Immunofluorescent Antibody Technique. Eighty percent of the sera were positive at a dilution of 1:32 and 45% at a dilution of 1:128. The authors conclude that this provides evidence of the endemic situation of Mediterranean Spotted Fever in the South of France.

Animals

[Results of a year's mycologic and immunologic surveillance of Candida in an intensive care ward].

Patients hospitalized in an intensive care unit must be considered to be exposed to a "high risk" in terms of candida infection. They often combine several of the factors favouring the development of "candida disease": generally deficient state, multiple antibiotics, iatrogenic or pathological immune depression. While certain patients who are admitted are already suffering from "candida infestation" (endogenous localization), the possibilities of exagenous infection are numerous. This study involved 63 patients spending at least one week in the department, from September 1977 to September 1978. Mycological (pharyngeal swab, urine culture, blood culture) and immunological (hemagglutination, immunoelectrophoresis, immunofluorescence) studies were carried out routinely on admission and then every week. Amongst the 63 patients studied, 12 were admitted with negative serology, which became positive during the first 10 days. 5 already had positive serology at the time of admission. From a mycological standpoint, the pharyngeal swab was frequently positive on admission (17 times out of 63). In 63 patients, the infection was acquired during the course of the hospital stay and, in this case, positive urine cultures were more regularly associated with a positive pharyngeal culture.

Candida

[Leishmaniasis in south-eastern France- -ecology, epidemiology, prophylaxis].

A study of the ecology, epidemiology and prophylaxis of Leishmaniasis in the southeast of France is reported; different methods of the survey are recorded. Between 1965 and 1975, 972 cases of canine Leishmaniasis and from 1968 to 1975 89 cases of visceral human Leishmaniasis and only 3 cases of oriental sore were observed in the "Bouches du Rhône", "Var" and "Vaucluse" Departments. The strains isolated from canine and human visceral Leishmaniasis had a malate dehydrogenase XI whereas Leishmania tropica had a MDH I; no wild animals have been found with Leishmaniasis. The suburbs of the towns, the hills in the center of Marseilles or surrounding Toulon as well as the villages are the principal foci of Phlebotomus perniciousus (96%) as the vector. The biotopes are isolated houses with little gardens surrounded by dry-stone walls exhibiting holes named "barbacanes", with chalky soil and xerophytes. The killing of infected dogs is the best protection of men whereas keeping dogs in sandfly-proof kennels from twilight until one hour after sunrise is best in order to protect this animal. This is quite different from the observations made by RIOUX in the Cevennes.

Animals

[Overview of dermatophytes in Mali].

517 isolations of dermatophytes collected in Mali are reported. The various species are described and the main findings are: --Trichophyton species are more common (85.5% isolated from scalp lesions and 77.5% from skin scrapings) than Microsporum species. --Trichophyton verrucosum and Microsporum canis have been found found for the first time in Mali. --Ill-defined clinical forms of scalp lesions caused by either T. schonleinii or T. soudanense occur in the subsaharian areas of the country.

Adult

[Persistence of visceral leishmaniasis in the southeast of France and recorded frequency of the disease in adults. Apropos of recent cases].

The authors report on 9 cases of mediterranean visceral leishmaniasis (Kala-Azar) collected in the south-eastern part of France in 1978. They emphasize the more frequent occurrence of this disease in adults than children. Out of the 40 cases detected in this region between January 1975 and December 1978, 22 affected adults (55 percent) moreover, Kala-Azar appears to occur particularly in adults with decreased general resistance and diagnosis may be difficult because classical clinical features are no complete.

Adult