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Biomedical subjects

M Quilici

Publications and source records attributed to M Quilici.

At least 19 recordsLinked to original sources

Multilocus enzyme electrophoresis analysis of Candida albicans isolates from three intensive care units. An epidemiological study.

To evaluate the mechanism and risk factor associated with the nosocomial acquisition of Candida albicans, a 3-month prospective study was conducted on non-neutropenic patients in three distinct intensive care units in distinct hospitals. A total of 43 samples from 19 patients has been typed by multilocus enzyme electrophoresis (MEE). Samples (24) from the deep pharynx of hospital staff members were also cultured and typed. Thirteen of the 19 enzyme loci studied were polymorphic. The 52 electrophoretic types were assigned to 67 isolates, each type was represented by one to five isolates; this proved the great diversity of the isolates. It appeared that most patients were colonized or infected with different C. albicans strains. This study pointed out a possible cross-infection between patients and hospital staff and between healthy members of the hospital staff, and also showed the successive stages of infection by different electrophoretic types. Intubation and respiratory equipment as surgery intervention were possible sources of observed infections.

Alleles↗

Comparison of PCR with direct examination of bone marrow aspiration, myeloculture, and serology for diagnosis of visceral Leishmaniasis in immunocompromised patients.

A PCR assay amplifying a repeated sequence from the Leishmania infantum genome was compared with direct examination of bone marrow aspirate, myeloculture, and serology for the diagnosis of visceral leishmaniasis in immunocompromised patients. Of 73 patients living in an area endemic for leishmaniasis and where visceral leishmaniasis was suspected by physicians, only 10 had an indisputable diagnosis of visceral leishmaniasis. None of the diagnostic tests performed in the study achieved 100% sensitivity for diagnosing visceral leishmaniasis. PCR exhibited superior sensitivity (82%) in comparison with bone marrow aspirate examination (55%) and myeloculture (55%). Our PCR assay also showed good specificity (97%), negative predictive value (97%), and positive predictive value (82%) even when all unconfirmed PCR results were scored as false positives. Serology exhibited good sensitivity (80%) and excellent specificity (100%), negative predictive value (98%), and positive predictive value (100%) in diagnosing new cases of visceral leishmaniasis but failed to diagnose relapses. We also observed consistent negative serological results using several different immunological detection methods for 2 of the 10 patients with confirmed cases of visceral leishmaniasis. This lack of serological reactivity persisted throughout the course of their infections. These results demonstrate the importance of using PCR as an aid in the diagnosis of visceral leishmaniasis in immunocompromised patients.

AIDS-Related Opportunistic Infections↗

Isolation and characterization of a repetitive DNA sequence from Leishmania infantum: development of a visceral leishmaniasis polymerase chain reaction.

To construct a DNA probe specific for protozoa that cause visceral leishmaniasis, we cloned Pst I fragments of Leishmania infantum genomic DNA into a Bluescript II SK vector. A clone of 4.3 kb that contained a highly repetitive sequence was isolated and cut with three restriction enzymes: Hae III, Rsa I, and Sau 3A. After a new molecular cloning step, we isolated and sequenced a 140-basepair (bp) fragment. Two oligonucleotides were synthesized to be used as primers for a polymerase chain reaction. Using this probe, we detected an amount of DNA equivalent to one promastigote of L. infantum. This probe showed a high specificity; all protozoa tested that cause visceral leishmaniasis and L. major (one of the causative agents of Old World cutaneous leishmaniasis) showed a 100-bp amplified sequence, whereas other Leishmania strains showed a signal of a different size or else no signal. Moreover, no amplified sequence was obtained with other pathogenic parasites tested (Trypanosoma brucei, T. cruzi, Plasmodium falciparum, Pneumocystis carinii, and Toxoplasma gondii).

Animals↗

Characterization of a circulating antigen involved in immune complexes in visceral leishmaniasis patients.

Complications of visceral leishmaniasis are explained in part by immune complex pathology, particularly nephritis. Using the polyethylene glycol precipitation method, we identified among these complexes a Leishmania infantum circulating antigen by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. Monoclonal antibodies were produced to specifically detect this antigen. This protein (molecular weight 51 kD) is a cytoplasmic antigen of L. infantum and its synthesis by promastigotes is related to stationary-phase culture. It was present in sera from dogs whose leishmaniasis was associated with nephritis, and it was found in the sera of 30% of human patients with visceral leishmaniasis. It was also detected in the sera of patients with cutaneous leishmaniasis, and it persists in the sera of clinically cured subjects.

Animals↗

[Contribution of immunoblot to the diagnosis and monitoring of toxoplasmosis in acquired immunodeficiency syndrome].

This study evaluates the potential value of immunoblot for serological survey of toxoplasmosis infection in HIV infected patients. This technique was applied to the detection of IgG, IgM, IgA and IgE antibodies to Toxoplasma gondii in serum and cerebrospinal fluid. We compared the patterns obtained from sera of immunocompetent and HIV+ subjects in different situations: absence of toxoplasmosis, primo-infection, chronic infection and reactivation of toxoplasmosis. IgA antibodies were demonstrated in sera of all HIV+ patients with chronic infection: so, these antibodies have any diagnosis value in this group. IgE were only detected by immunoblot when clinical symptoms of toxoplasmosis occurred in cases of HIV+ patients with reactivation of the parasitosis; previously, these subjects presented a serological rise of IgG specific antibodies. In ten cases of neurotoxoplasmosis immunoblot allowed detection of IgA and IgE antibodies in serum and CSF and demonstrated their intrathecal synthesis in three cases. In conclusion immunoblot is a powerful technique for detection of IgA and IgE to Toxoplasma gondii. Demonstration of IgE antibodies seem to be a good criterion to evaluate the evolutivity of the parasitosis in HIV patients.

AIDS-Related Opportunistic Infections↗

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↗

[In vitro evaluation of the sensitivity to fluconazole of different species of yeasts isolated in pathology].

In a previous study, the authors developed a technique for evaluating the in vitro susceptibility (or resistance) of Candida albicans to fluconazole, using casitone broth and agar. Photometric readings of growth in liquid media proved more accurate for evaluating antifungal activity and consistently agreed with clinical findings in all studied cases. This method was consequently extended from C. albicans to other yeasts recovered from high-risk patients (C. glabrata, C. famata, C. tropicalis, C. krusei, C. pseudotropicalis, C. parapsilosis, etc...). High resolution antifungal assay medium (broth and agar) and casitone medium (broth and agar) with or without agitation (Autobac System) were used to study the activity of fluconazole against approximately one hundred yeast strains. MICs above 3.12 micrograms/ml were found for several strains, particularly belonging to the C. glabrata and C. krusei species. These values are equal to or greater than serum levels achieved during treatment with fluconazole, a fact which raises practical questions concerning fluconazole therapy and may explain the failure of fluconazole to eradicate yeasts in some patients.

Candida↗

Ecdysteroid-like compounds in human urine: they can occur in the absence of any parasitic infection.

Ecdysteroids (compounds related to 20-hydroxyecdysone, the insect molting hormone) can appear in the blood and urine of man, as a result of an infection with helminths. It has been assumed that the products are released by parasites. However, we found that the phenomenon is not restricted to helminthiases, but is widely spread among patients suffering from various diseases or injuries: twenty percent of hospital in-patients had urine highly positive in our test. This was due to the appearance of immunoreactive compounds not found in healthy people. Among them, one was remarkable for being largely predominant in some patients. These findings indicate that the origin and significance of ecdysteroids in man should be reconsidered. Since they appear only in association with severe pathological conditions, they could be of potential interest as a clinical marker.

Aged↗

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↗

[Laboratory's controls of antifungal treatment by the fluconazole of the candidiasis in immunocompromised patients].

The use of antifungal drugs in immunocompromised patients impose to the laboratory the control of the efficacy of these therapy. With fluconazole, one of the most recent antifungal agents these control use a special method (Central Research Pfizer) different of those they are used with others antifungals. We have comparatively tested, using MIC technic four broth mediums (High Resolution medium (Oxoid) YMB (Difco) YNB dextrose (Autobac) and Casitone) and three agar mediums (HR, YMA, Casitone) incubated at 28 degrees C for 24 and 48 h. The strains of yeasts are isolated from oro-pharyngeal prelevements on HIV antibody positive patients observed during six to twelve months and eventually treated by fluconazole. Sixty patients are controlled, 33 give one or more positive cultures with 74 strains of C. albicans and four other yeasts. By determination of the MICs with seven different methods we find any resistant strains with the MICs range from 3.12 to 12.5 or 25 micrograms/ml.

Acquired Immunodeficiency Syndrome↗

Ecdysteroids in urine of African patients infected with helminths.

The insect molting hormone and related compounds (ecdysteroids) have been found in patients infected with helminths. To investigate this phenomenon, we quantified and analyzed the urinary ecdysteroids in Malian subjects suffering from various helminthiases, as well as in Europeans. Very high titers (up to 100 nM) were found in some patients, whereas healthy persons had a basic level of 4 nM only. The high RIA activity was mainly due to two compounds. One of them was remarkable for being present in all the positive samples; it comigrated with the 20-hydroxyecdysone standard, both in HPLC and in TLC. The origin and the physiological significance of these compounds are questionable, since there was no clear relationship between their levels and the severity of the diseases. Numerous patients who were heavily infected had normal titers. Nevertheless, there is no doubt that high concentrations of ecdysteroid-like compounds in human urine indicate a pathological condition.

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↗

[Synergic effect of 5-fluorocytosine and imidazole derivatives against yeast strains resistant to 5-fluorocytosine].

Antifungal agents associations are widely used in therapy of deep mycotic diseases, particularly amphotericin B-5-fluorocytosine association. Synergistic effect has also been described between 5-fluorocytosine and imidazole derivates. The authors have tested here eventual synergy between 5-fluorocytosine and imidazole derivatives (miconazole, ketoconazole, fluconazole, itraconazole) against 57 years isolates resistant to 5-fluorocytosine by a semi-automated methods in liquid medium (Yeast Nitrogen Base and Brain Heart Infusion). The synergistic effect between 5-fluorocytosine and antifungal imidazoles varies widely with the drug tested. It's more frequent with ketoconazole. Itraconazole and fluconazole present very little synergistic effects in vitro.

Antifungal Agents↗

Carbon assimilation tests: substrates assimilation profiles.

Liquid medium assays for yeasts carbon assimilation tests are the more precise but longer methods. For rapid and automated yeasts identification purposes we analysed the assimilation of 34 carbon compounds by 149 reference strains. Assays were carried in liquid shaken medium (Autobac system) and readings were nephelemetric. Valuable results are obtained in 72 hours and their analysis allowed us to classify substrates for their ability to minimize the number of doubtful results.

Alcohols↗