Médecine sciences : M/S
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Human beings are constantly exposed to pathogens. The innate immune system is the first line of defense against microbes. It has evolved to recognize conserved microbial motifs (PAMP or pathogen-associated molecular patterns) thanks to a limited array of receptors termed pattern recognition receptors (PRR). ⋯ In contrast, engagement of various PRR in the recently identified inflammasome complexes lead to activation of a cysteine protease, caspase-1. This inflammatory caspase has a dual activity: it triggers the release of very potent proinflammatory cytokines IL-1β and IL-18 and, an hyperinflammatory cell death termed pyroptosis. In this review, we describe the inflammasome receptors and their ligands, the molecular mechanisms leading to the assembly of this innate immune platform and the role of the inflammasome during viral and bacterial infections.
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Mucormycosis is an infection caused by filamentous fungi of the Mucorales order. The predisposing factors are mostly diabetic ketoacidosis and severe immunosuppressive conditions such as prolonged neutropenia, steroid or T-cell suppressor therapy, solid organ transplantation or allogeneic hematopoietic stem cell transplantation. Mucormycosis can also occur in immunocompetent patients, especially after trauma, burns or direct inoculation of the fungi (e.g. intravenous drug abuse). ⋯ Clinical and radiological aspects are similar to those observed in other invasive filamentous fungi infections such as invasive aspergillosis, fusariosis or scedosporiosis. CT-scan or MRI are mandatory to assess the extension of the lesions. The diagnosis remains difficult and is often delayed resulting in a poor outcome.
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Mucormycosis is a life-threatening invasive fungal infection that arises among immunocompromised patients (haematological malignancies, solid organ transplantation, diabetes mellitus). The most frequent sites of infection are pulmonary, rhinocerebral, cutaneous and disseminated. Reversal of the underlying conditions is mandatory for controlling mucormycosis. ⋯ The first-line chemotherapy of mucormycosis includes high-dose liposomal amphotericin B (≥ 5 mg/kg/day). The duration of antifungal chemotherapy is not defined but guided by the resolution of all associated symptoms and findings (usually 6-8 weeks). Maintenance therapy/secondary prophylaxis by posaconazole has to be considered in persistently immuno compromised patients.