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Biomedical subjects

J F Magnaval

Publications and source records attributed to J F Magnaval.

At least 19 recordsLinked to original sources

Scedosporium apiospermum mycetoma with bone involvement successfully treated with voriconazole.

Treatment of Scedosporium apiospermum mycetoma usually requires limb amputation. A 49-year-old woman, from Ivory Coast, was diagnosed with Madura foot in 1995. She failed to respond to several treatments including itraconazole, fluconazole and co-trimoxazole, and refused limb amputation. In December 2002 she was admitted to hospital in France with a painful, swollen right leg and foot. She had no fever and C-reactive protein was 120 mg/l. Magnetic resonance imaging (MRI) confirmed the destruction of tarsus bones with a tibia extension. Voriconazole (400 mg/day) treatment was initiated in March 2003; a significant clinical improvement was observed within 4 months as confirmed by C-reactive protein (16 mg/l) and MRI. Voriconazole was maintained for 18 months with good tolerance. Cholestasis appeared after the first month and remained stable. In October 2004 voriconazole was discontinued due to side effects on the liver (alanine aminotransferase 17 times the normal level); MRI showed impressive regression of bone lesions. As of July 2005, the patient remains clinically well. Voriconazole appears to be a promising drug for the treatment of S. apiospermum mycetomas.

Antifungal Agents↗

Comparison between two amplification sets for molecular diagnosis of toxoplasmosis by real-time PCR.

PCR is now commonly applied to the diagnosis of toxoplasmosis. Although several methods are available, comparative studies are few, making it difficult to compare the performance of each technique. We compared the sensitivities of two real-time PCR assays through a prospective study on fetuses, neonates, and immunocompromised patients and on the ocular diagnosis of toxoplasmosis. The first system targeted the widely used B1 gene (GenBank accession number AF179871) while the second (RE) targeted a more recently described sequence repeated roughly 200 to 300 times (GenBank accession number AF146527). We demonstrated that molecular diagnosis requires the duplication of PCR assays, especially with the B1 system, as only one PCR was positive in 33.3% of cases. Our study showed that the RE target was more sensitive for all biological samples (amniotic fluid, placenta, aqueous humor, whole blood, and cerebrospinal and bronchoalveolar fluids) and significantly improved the performance of the diagnosis of toxoplasmosis. Taking into consideration all clinical samples, the mean gain in the crossing point value was 4.2 +/- 1.7 cycles and was even more significant for amniotic fluid (5.8 +/- 1.7 cycles).

Amniotic Fluid↗

[Treatment of cosmopolitan parasitic diseases].

Cosmopolitan parasitic diseases are often unrecognized and misdiagnosed. Treatment can be difficult due mainly to a lack of the therapeutic drugs. The purpose of this review is to update knowledge about the therapy of anisakiasis, cystic echinococcosis, fascioliasis, giardiasis, pinworm/tapeworm infections, strongyloidiasis, and toxoeariasis.

Global Health↗

[Parasitic dead-end: update].

Parasitic dead-ends occur when a parasite is unable to establish a permanent interaction in an unnatural host. Although the likelihood of successful reproduction by the pathogenic agent is nul, parasitic dead-end heralds capture of new parasites and therefore expansion of the host range. Angiostrongyliasis due to A. cantonensis or A. costaricensis, anisakiasis, Ancylostoma caninum infection, gnathostomiasis and sparganosis are undoubtedly emerging zoonoses of particular medical interest. Prevention of these diseases relies on abstinence from eating raw meat from invertebrates or cold-blooded (poikilotherm) vertebrates (e.g. used in exotic dishes). These guidelines must be included in recommendations to travelers.

Ancylostoma↗

Ex vivo and in vitro impairment of CD36 expression and tumor necrosis factor-alpha production in human monocytes in response to Plasmodium falciparum-parasitized erythrocytes.

Severe malaria is associated with the failure of host defenses to control parasite replication, with the excessive secretion of proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha), and with the sequestration of parasitized erythrocytes (PEs) in the microcirculation of vital organs. The scavenger receptor CD36, known as a major sequestration receptor, has also been identified as an important factor in mediating nonopsonic phagocytosis of PEs by monocytes and macrophages. The specific consequence of this phagocytosis is a decrease in parasite-induced TNF-alpha secretion. We evaluated the variations in CD36 level and in lipopolysaccharide (LPS)-induced TNF-alpha production in monocytes from Plasmodium falciparum-infected patients and in vitro in the presence of PEs. Both the monocytes from infected patients and from in vitro culture showed a decrease of CD36 expression and a reduced production of TNF-alpha induced by LPS. Using incubation assays with no contact between monocytes and PEs, or in the presence of a soluble supernatant obtained from the incubation of monocytes and PEs, this study shows that decreased CD36 expression was posttranscriptional and not directly related to PEs phagocytosis. In addition, these culture models suggest that the reduced capacity of TNF-alpha production occurred in 2 phases. The early phase (24 hr) appeared to be CD36 dependent and the second phase (48 hr) was due to a soluble factor produced by PEs. These observations suggest that the control of the TNF-alpha production in malaria by monocytes was not entirely dependent on the phagocytosis of PEs by CD36 and that soluble factors produced by PEs could play a role in this process.

Animals↗

Contribution of PCR-based methods to diagnosis and management of imported malaria.

Since the first description, in 1990, of the diagnosis of Plasmodium falciparum infection by polymerase-chain-reaction (PCR), the role of this kind of molecular method in laboratory diagnosis of imported malaria is still a topical question. Various molecular assays have been used, the first of which was hybridization using labeled probes in 1984. When compared to thick blood smear, this test displayed a sensitivity ranging from 65% to 81% and specificity was close to 100%. The next technical improvement was the introduction of the so-called polymerase chain reaction (PCR), the principle of which was described in 1985. In 1993, a PCR-based assay detecting all four Plasmodium species was published, followed by different variants of this method. By the turn of the century, novel real-time PCR slashed workaround time, which dropped from 2 1/2 hours to less than 1 hour. Moreover, automatic reading with no human action on PCR products reduced the risks of contamination. The first application of real-time PCR to the diagnosis of malaria was published in 2001. PCR-based assays were found to be more sensitive than all conventional methods. Variations in sensitivity were probably due to different medical practices as well as to the proportion of various types of subjects (travelers under chemoprophylaxis, immigrants from malaria-endemic areas) in the population undergoing malaria diagnosis. The target of the primers was also of crucial importance: for the detection of P. falciparum, the most efficient assays amplified either the gene SSUrRNA, or Pf155/RESA, or Cox 1. Specificity of PCR results is guaranteed by the nature of the target for primers or probes, as determined by the studies of the Plasmodium genome whose results are available in GenBank. PCR use often corrected the results of Plasmodium species identification by microscopy and PCR-based methods were found to be the most efficient for the detection of mixed infections. Concerning the diagnosis of imported malaria, it appears clearly that PCR should be considered as second-line method which can be especially interesting, as a negative result rules out malaria in febrile patients. However, the use of PCR assays appears to be restricted to health centers, such as University Hospitals, for whom malaria identification is an important and routine problem. In the future, the detection of mutations related to drug resistance could be used to orient anti-malarial therapy.

Automation↗

Comparative assessment of conventional PCR with multiplex real-time PCR using SYBR Green I detection for the molecular diagnosis of imported malaria.

For the diagnosis of imported malaria, optical or immunochromatographic methods are known to be less sensitive and less specific than PCR-based methods, which are conversely more complicated and time-consuming. An original strategy, based upon the sequential use of a multiplex competitive real-time PCR detecting Plasmodium falciparum or Plasmodium spp. infection, followed by, if necessary, a single real-time PCR for species identification, was therefore performed and then tested versus conventional PCR in routine conditions. Conventional PCR has been used since October 1999 in the Department of Parasitology, University Hospitals in Toulouse, as a 2nd line diagnostic method. Out of 183 patients tested, 48 were found to be harbouring a falciparum infection by conventional microscopy, 60 by conventional PCR and 60 by multiplex competitive real-time PCR. Nine further patients had a non-falciparum infection, and concordant species identifications were obtained by both conventional PCR and single real-time PCR. The major value of PCR-based methods, when compared to microscopical techniques, was to ascertain the negativity of a suspect sample. Moreover, real-time PCR allows simplification of the operating procedure, with a diagnosis being made within 2 h.

Animals↗

[Diagnosis of imported malaria with multiplex PCR on LighCycler apparatus].

For the diagnosis of imported malaria, a competitive multiplex PCR using LightCycler was developed and compared for 3 months with a traditional PCR method. Hundred eighty three patients were tested by these 2 techniques of molecular diagnosis: 60 were positive for P. falciparum, 9 were positive for other Plasmodium species and 114 were negative. The LightCycler method was found in total agreement with the traditional PCR.

Animals↗

One year's experience with the polymerase chain reaction as a routine method for the diagnosis of imported malaria.

Given the problems encountered in westernized countries with the laboratory diagnosis of malaria, namely sensitivity of the conventional methods and detection of mixed infections, a polymerase chain reaction (PCR)-based diagnosis has been developed and routinely used. The PCR used two sets of primers to simultaneously detect any infection due to the genus Plasmodium, or to the species P. falciparum. The PCR results were available within six hours. Five hundred twenty-nine patients were tested, of whom 136 were found positive by the PCR, and only 104 by the quantitative buffy coat (QBC) method. The 32 discrepancies were analyzed on the basis of the clinical data, and technical, molecular, and sequencing findings to ascertain the presence of Plasmodium DNA. The PCR-based diagnosis of malaria appeared to be a useful tool that was suitable as a second-line method when the results of conventional techniques were negative in patients presenting a syndromeconsistent with malaria, as well as yielding an accurate species identification.

Adult↗

[Toxocara canis meningoradiculitis].

Various neurological pictures attributed to human toxocariasis are sparsely reported in the literature. A case of toxocaral infection presenting as meningoradiculitis is described herewith. Etiological diagnosis was oriented by the finding of an eosinophilia in the spinal fluid, then confirmed by the result of the immunodiagnosis of toxocariasis from both serum and spinal fluid.

Acetates↗

Eosinophil cationic protein as a possible marker of active human Toxocara infection.

BACKGROUND: Human toxocariasis is a common, worldwide helminthozoonosis that may elicit syndromes including various allergy symptoms. The diagnosis relies upon specific serology. However, this parasitosis is often self-limiting, and many subjects have residual antibodies, thus making differential diagnosis quite difficult when blood eosinophilia, a commonly accepted criterion of active helminthiasis due to tissue-dwelling parasites, is lacking. METHODS AND RESULTS: We present a patient with chronic irritant cough displaying negative allergologic screening, normal blood eosinophilia, but positive toxocariasis immunodiagnosis. Therefore, this case presented the fortuitous association of an unexplained allergic picture with residual anti-Toxocara antibodies. In an attempt to distinguish between active and past toxocaral infection, the subject's level of eosinophil cationic protein (ECP) was assessed and then compared to those of four control groups, namely, healthy volunteers, subjects presenting anti-Toxocara residual antibodies, patients with various helminthiases, and patients with active toxocaral disease. Since the patient's ECP level was found to be sharply elevated, we hypothesized that viable Toxocara larvae were still present in the tissues, and the patient was given anthelmintic therapy. At the control checkup, the cough had waned and the ECP level had decreased to below the mean value observed in both healthy subjects and in subjects with past toxocaral infections. CONCLUSIONS: These data suggest, first, that patients presenting unexplained allergic syndromes should be checked for helminthiases, even if blood eosinophilia is lacking, and, second, in such subjects displaying positive toxocariasis immunodiagnosis, ECP assessment would be a useful marker to distinguish between active and past toxocaral disease.

Animals↗

Highlights of human toxocariasis.

Human toxocariasis is a helminthozoonosis due to the migration of Toxocara species larvae through human organism. Humans become infected by ingesting either embryonated eggs from soil (geophagia, pica), dirty hands or raw vegetables, or larvae from undercooked giblets. The diagnosis relies upon sensitive immunological methods (ELISA or western-blot) which use Toxocara excretory-secretory antigens. Seroprevalence is high in developed countries, especially in rural areas, and also in some tropical islands. The clinical spectrum of the disease comprises four syndromes, namely visceral larva migrans, ocular larva migrans, and the more recently recognized "common" (in adults) and "covert" (in children) pictures. Therapy of ocular toxocariasis is primarily based upon corticosteroids use, when visceral larva migrans and few cases of common or covert toxocariasis can be treated by anthelmintics whose the most efficient appeared to be diethylcarbamazine. When diagnosed, all of these syndromes require thorough prevention of recontamination (especially by deworming pets) and sanitary education.

Animals↗

A retrospective study of autochthonous strongyloïdiasis in Région Midi-Pyrénées (Southwestern France).

In order to assess the existence of autochthonous strongyloïdiasis, a retrospective study was carried out in Région Midi-Pyrénées (Southwestern France). Among 63 strongyloïdiasis cases diagnosed at the Consultation of the Department of Parasitology, CHU Purpan in Toulouse, 17 patients (27%) were identified as likely harboring an autochthonous infection. The diagnosis was based upon the results of either Baermann's method for stool examination, or indirect fluoroimmunoassay using Strongyloïdiasis ratti L3 larvae as antigen. Repeated contact with soil or mud, due to occupation or gardening, was found in 13 patients. Twelve cases lived in the upper basin of the Garonne River. The clinical and laboratory findings were similar to those reported by the literature. No case of larva currens was observed. These results suggest that a permanent transmission of strongyloïdiasis possibly exists in Région Midi-Pyrénées, requiring further prospective studies.

Adult↗

Five cases of ocular toxocariasis confirmed by serology.

We report 5 cases of ocular toxocariasis in Korean adults complaining of visual impairment along with floating or bubbling sensation. Fundoscopic examination revealed a retinal detachment along with exudate in 4 cases. They all showed typical reaction by ELISA and immunoblot against Toxocra excretory-secretory antigen. One case showed high level of anti-Toxocara IgE antibodies (34,000 Toxocara units/L) as well as increased level of serum total IgE antibodies and the specific IgE antibodies for 3 inhalant antigens, suggesting that high level of anti-Toxocara IgE antibodies was associated with an atopic status. Clinical manifestations were improved after the sequential use of steroids then mebendazole. We also suggest that ocular toxocariasis should be thoroughly investigated even when an evocative uniocular inflammatory lesion is encountered in peripheral retina without a systematic disease.

Adult↗