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Biomedical subjects

F Guilbert

Publications and source records attributed to F Guilbert.

At least 55 records · Page 3Linked to original sources

[Odontogenic myxoma. A histoenzymologic and ultrastructural study. Apropos of 5 cases].

The myxoma of the jaws represent 8% of the odontogenic tumours in our series (324 cases). The 5 cases described here were studied by histoenzymological and electron microscopic methods. The first method demonstrated in the majority of tumoral cells a high level of activity of alkaline phosphatases and ATPases similar to that noted in odontoblasts of the dental pulp. In addition, an acid phosphatase activity was also present in numerous cells but usually at a low intensity. Ultrastructurally, the tumour was composed of 3 main cellular types: young round cells with numerous ribosomes; stellate secretory cells with well-developed granular ergastoplasma and Golgi apparatus; fusiform cells with characteristics of fibroblasts. Some macrophages and myofibroblasts were also present. The intercellular substance was granulofilamentous and in one of our cases calcifications were obvious upon some collagen fibers. All these results seem to corroborate the hypothesis of odontogenic nature of the tumour. Early odontogenic induction induces the transformation of fibroblasts into cells with enzymatic activities similar to those of odontoblasts and the calcification of collagen fibers seen in one of our cases would express an early mineralization.

Esterases

[Angiomas of the jaws. Diagnostic and therapeutic problems (apropos 12 cases)].

Difficulties encountered during surgery on maxillary angiodysplasias were studied in relation to case-reports of patients treated in the stomatology and maxillofacial surgery unit directed by professor Vaillant, Hôpital Salpêtrière, Paris. Findings allowed certain conclusions to be drawn with respect to diagnostic and therapeutic features and to compare these with those reported in the international literature.

Adolescent

[Mandibular mucoepidermoid tumor].

One case of mandibular mucoepidermoid tumour was observed in a 57 years old man. A progressive swelling of the mandible was shown with an osteolytic feature on roentgenograms. It was treated by hemimandibulectomy. Grossly, the neoplasm was partly cystic. Histologically, it was mainly composed of intermediate clear cells. Its ultrastructure was quite similar to that of mucoepidermoid tumours in other sites. Heterotopic salivary lobules, though lacking in our case, seem to play the major role in the genesis of these tumours.

Carcinoma

[Benign tumors and mandibular resection. The place of resection grafts in the treatment of benign tumors of the mandible].

Data were analyzed from case-reports of 80 patients undergoing resection graft procedures for benign mandibular tumors, and operated upon and followed up in the Stomatology and maxillo-facial surgical Unit, Hospital Salpêtrière, Paris from 1970 to 1984. In 27 cases surgery was by first intention; in the others it followed one or several previous operations, their multiplicity sensibly affecting the decision to operate and the development of postoperative suppurations.

Adolescent

[Parotid sialadenosis. A histoenzymologic and ultrastructural study].

A case of sialadenosis was studied by means of several morphological methods (light microscopy with micrometric measurement, transmission and scanning electron microscopy, immunopathology, histoenzymology). In that disease, these investigations seem to corroborate the hypothesis of a dyscrinism, true perturbation of the salivary excretion with storage of secretory granules in the cells and consecutive hypertrophy. This dyscrinism should result from a deterioration of branches of autonomic nervous system. In the case reported here, no etiology was proved but the hypothetic part of a recent antiulcerous treatment by Tagamet was suggested.

Adult

Histoenzymological and ultrastructural study of a bifocal calcifying epithelial odontogenic tumor. Characteristics of epithelial cells and histogenesis of amyloid-like material.

A calcifying epithelial odontogenic tumor, simultaneously located in the two jaws (maxilla and mandible) was examined by histochemical and electron microscopic methods. Squamous tumor cells without secretory polarity were different from those of common ameloblastoma. High activities of alkaline phosphatase and ATPases were demonstrated by light and electron microscopy on the cytoplasmic membrane, findings similar to those in the stratum intermedium cells of the normal dental germ from which these tumor cells seem to arise. The tumor cells, like preameloblasts of the dental germ, also produce a granulo-filamentous material in intracytoplasmic vesicles and discharge it into the stroma. This "pseudo-amyloid" substance represents an abnormal protein of the enamel matrix and calcification, mainly occurring in that substance, might be an attempt at mineralization.

Adenosine Triphosphatases

[Hemangiopericytoma of the orofacial region].

Prognosis in 11 cases of hemangiopericytoma of the orofacial region (9 buccal and 2 parotid tumors) was, as with these lesions in other zones, an uncertain entity: 4 local recurrences within 8 months to 7 years; one fatal outcome after 3 years from pulmonary micrometastases. Histologic classification of these tumors into 3 cytologic groups of increasing malignancy (I to III) is a function of the number of their cytologic anomalies. They are also divided according to their overall morphology into poorly differentiated, differentiated and sclerous types. Positive correlations between structure and cytologic criteria of malignancy and structure and clinical course have been demonstrated. Ultrastructural examination in 2 cases showed polymorphic endothelial, fibroblastic and smooth muscle cells in contact with adult tumoral pericytes. This suggests the origin of the tumor from young cells of multiple potency rather than from adult pericytes.

Adolescent

[Wide excision in cancer of the tongue: the choice of approach, modalities of reconstruction].

Surgical treatment of extensive carcinoma of the tongue requires reconsideration at the present time: firstly, because the efficacy of other therapeutic measures is rapidly suppressed by the size of the tumors, and there is not theoretical reason for excluding extensive surgery, and secondly, because esthetic and functional sequelae of these bloody treatments have been totally modified by the introduction of new reconstructive techniques. Based on a series of 16 cases treated during a one-year period, the conditions for surgery of vast malignant tongue tumors (T3, T4, N indifferent) are analyzed, and findings emphasize the need for a wide approach. Clear exposure is obtained, the continuity of the mandibular arch is conserved, and effective anatomical and functional reconstruction obtained of tissues sacrificed by the musculocutaneous flaps.

Glossectomy

[Bifocal odontogenic calcified epithelial tumor (Pindborg's tumor). A morphologic and ultrastructural study].

Histoenzymologic and ultrastructural examinations were conducted on a doubly located calcified odontogenic epithelial tumor. The cells of the tumor, developing in both the maxilla and mandible, differed from those of the common ameloblastoma, being all of the malpighian type without any secretory polarity. Furthermore, optical and electronic microscopy showed evidence of marked alkaline phosphatases and ATPases activity in their numerous peripheral microvilli. These identical activities to those of the stratum intermedium could suggest the origin of the tumor from these latter cells. But, like the preameloblasts of the dental germ, these tumoral cells produce in their intracytoplasmic vesicles and then excrete into the stroma, a granulofilamentous substance, pseudo-amyloid, which could thus represent an abnormal protein of the enamel matrix. The calcifications, mainly present in this amyloid-like substance, are the expression of an attempt to mineralize this abnormal matrix. Stromal calcifications may result from a sketchy odontogenetic induction, as shown by the intense activity of ATPases and alkaline phosphatases on the fibroblastic cytoplasm membranes.

Adult