From phaeohyphomycosis to disseminated chromoblastomycosis: A retrospective study of infections caused by dematiaceous fungi.

OBJECTIVE: Infections caused by dematiaceous fungi are more common in tropical and subtropical areas. We aimed to describe the clinical, microbiological and therapeutic aspects of case patients diagnosed at a University Hospital located on an Indian Ocean island. PATIENTS AND METHODS: We performed an observational retrospective study of infections caused by dematiaceous fungi diagnosed at the University Hospital of Saint-Pierre, Reunion, from 2000 to 2015. Mycological identifications were performed at the National Reference Center for Invasive Mycosis and Antifungal Agents (Paris). RESULTS: The review of clinical and microbiological data of 11 patients identified revealed that five were infected by dematiaceous fungi. Two had cutaneous phaeohyphomycosis, two had cerebral phaeohyphomycosis and one had cutaneous chromoblastomycosis with brain and potentially medullary dissemination. Skin lesions and cerebral abscesses were quite varied. CONCLUSION: Infections caused by dematiaceous fungi are rare. Medullary and brain localizations are extremely rare, especially for chromoblastomycosis. Cutaneous manifestations of phaeohyphomycosis are varied; diagnosis is thus more difficult. It is therefore important, when confronted with a chronic tumor-like lesion in endemic areas, to perform a biopsy for pathology and fungal culture. While surgical excision is not always sufficient, medical treatment of these infections is not standardized, but relies on an azole, which can be associated with another antifungal agent.

A simple method for SEM examination of sectioned diatom frustules.

We describe an innovative yet straightforward method to obtain high quality thin sections of diatom exoskeletons for observation by scanning electron microscopy (SEM). The use of this new technique allows for clear observations of some ultrastructural valve features, including the raphe, which are generally difficult to observe and describe accurately using transmission electron microscopy analysis of thin sections or SEM of randomly fractured diatom valves. In addition, because this method involves the complete removal of the organic content of the diatom cells, resulting in clean and mostly undisturbed skeletal thin cross-sections, even the intact valvar structures of weak girdle bands can be studied.

[Use of a new process of metallic shadowing by cathodic vaporization for scanning electron microscopy of tegumental products of insects]. / Utilisation du nouveau procédé de métallisation par pulvérisation cathodique, pour l'étude en microscopie électronique par balayage, des productions tégumentaires des insectes.

In scanning electron microscopy, the recent process, not yet much used, of coating subjects with gold by cathodic sputtering, allows one in biology and especially in entomology, to visualize microreliefs, habitually masked, when the old technique called evaporating technique, was used. This process effectively allows one to deposit a very much thinner layer of metal and, because it is performed at room temperature, prevents artifacts caused by the high temperature necessitated by the other technique, whose previous results nevertheless remain generally correct.

[Examination of the uterine cervix using the scanning electron microscope]. / Examen du col utérin au microscope électronique à balayage

Scanning by electron microscopy of the cervix of the uterus allows us to study the various aspects, both normal and pathological, as well as the architecture of sections of the organ. All the same, as in all practical examinations carried out using scanning we have to beware of pictures that are but artefacts due to the method of preparation. The views obtained from a normal cervix of from pathological cervices show very different aspects. In the normal cervix the surfaces are more or less smooth and the architecture of the deeper levels shows a thick and regular texture. Infectious lesions of the outer aspect of the cervix show punched-out patterns, like craters, which penetrate more or less deeply into the sub-epithelial plane. While cervical dysplasia shows little except perhaps a more or less bossed-up epithelial surface, cancer of the cervix on the other hand shows a pavement pattern which is irregular. The pavements are formed by buds which are separated by faults which are more or less deep. In section the structures show a degree of disorientation in the texture. After treatment with radium the appearance is rather like ground glass of spiders webs and the architecture of the structures seems to be pock-marked and chaotic.