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C Prost

Publications and source records attributed to C Prost.

At least 91 records · Page 5Linked to original sources
PubMed1991

[Acne fulminans triggered by isotretinoin therapy].

An 18-year old male patients with tetracycline-resistant acne vulgaris was prescribed isotretinoin in daily doses of 0.5 mg/kg. Ten days later, he developed an acute episode of acne fulminans which was regressive. Subsequently, two attempts were made at reintroducing isotretinoin; the first one was followed by a new episode of acne fulminans and the second one, by ordinary myalgias, while the patient was still under corticosteroid therapy. A search in the literature yielded 14 cases of acne fulminans that had possibly been induced by isotretinoin. Doses and intervals between medication and acute manifestations varied, and the responsibility of isotretinoin was seldom demonstrated. Associations with erythema nodosum myalgias and arthralgias have been described. This rare adverse effect of isotretinoin therapy must be known. Its course and treatment are not different from those of ordinary acne fulminans.

Acne Vulgaris↗
PubMed1991

Transient intraepidermal bullous reaction after skin graft for toxic epidermal necrolysis. Ultrastructural and immunohistochemical features similar to those of inherited epidermolysis bullosa simplex.

Blister formation in skin graft donor or recipient sites is uncommon. We describe a 49-year-old female patient with bullae in sites of grafts used in the treatment of toxic epidermal necrolysis. Generalized loss of skin developed 3 weeks after she had ingested phenobarbital. Sixty days after the beginning of the toxic epidermal necrolysis, the reepidermization was only 80% and skin grafts were placed on lower-extremity and abdominal wounds using the first healed sites as donor sites. Several bullae and erosions were noted on grafted areas 3 weeks later. Skin biopsy specimens revealed separation at the dermoepidermal junction, and no autoantibodies were detected by direct and indirect immunofluorescence. Electron microscopy demonstrated that the blister was formed through the basal keratinocytes and that the dermoepidermal junction, including hemidesmosomes and anchoring fibrils, was normal. Immunofluorescence mapping was performed using polyclonal antibodies from the serum of patients with bullous pemphigold and epidermolysis bullosa acquisita and monoclonal antibodies against GB3 antigen and collagen type VII. All but the bullous pemphigold serum gave positive results; only faint and focal staining of the dermoepidermal junction was observed with bullous pemphigold serum. These findings are the same as those encountered in hereditary epidermolysis bullosa simplex. A biopsy performed 1 year later in the same site as the first one revealed that bullous pemphigold antigen was normally expressed. Keratinocytes autografted in the treatment of toxic epidermal necrolysis may become transiently, functionally abnormal because of the alteration of recipient sites.

Blister↗
PubMed1990

[Epidemiology of alveolar echinococcosis in France. 1. Intestinal helminths in the red fox (Vulpes vulpes L.) from Haute-Savoie].

In the course of an epidemiological survey concerning the alveolar echinococcosis and its causative agent, Echinococcus multilocularis, the autopsies of 150 wild red foxes captured in the department of the Haute-Savoie between December 1983 and August 1988 disclosed 139 cases of intestinal helminthiasis with cestodes and nematodes; no trematode was found. Multiple infections were frequent. The cestoda recorded consist of the following species: Taenia crassiceps: 44 cases (29%); Echinococcus multilocularis: 34 cases (23%); Taenia polyacantha: 22 cases (14%); Mesocestoides litteratus: 7 cases (4.6%); Amoebotaenia paradoxa: 1 case (0.6%). The Nematoda concerned are: Uncinaria stenocephala: 79 cases (52%); Toxocara canis: 67 cases (44%); Toxascaris leonina: 16 cases (10%); Trichuris vulpis: 12 cases (8%); Pterygodermatites affinis: 8 cases (5%); Trichostrongyloidea sp.: 5 cases (3%). The animals were not examined for Trichinella spiralis. The results are compared with those observed anteriorly in the province of Auvergne (France).

Animals↗
PubMed1990

Studies of cicatricial pemphigoid autoantibodies using direct immunoelectron microscopy and immunoblot analysis.

We studied 11 consecutive patients with classical cicatricial pemphigoid (CP) using direct immunoelectron microscopy (IEM) and Western immunoblotting analysis. Direct IEM performed in the skin or gingival mucosa revealed in all 11 CP patients that immunoglobulins and complement deposits were usually thick and discontinuous along the dermoepidermal junction, mostly localized on the lamina densa and occasionally in the lamina lucida. By direct IEM, the ultrastructural aspect in CP differs from the pattern observed in bullous pemphigoid (BP) and from that of chronic epidermolysis bullosa acquisita (EBA). Nine CP patients were studied by Western immunoblotting and, of these nine, only two had detectable anti-basement membrane zone (BMZ) antibodies by indirect immunofluorescence on salt-split skin. By immunoblotting performed on protein extracts of heat-separated epidermis, eight out of the nine CP sera specifically reacted with two protein bands of approximately 230-240 kD and 180 kD, similar to those recognized by BP sera in co-migration experiments. By immunoblotting on skin BMZ extracts, none of these nine CP sera recognized the 290-kD major polypeptide of EBA antigen. Taken together, these results suggest that, in CP, the target-antigen, as identified on immunoblots, is similar to BP antigen, but with an abnormal expression within the dermoepidermal junction of patients, which may in part explain the scarring course of the disease.

Adult↗
PubMed1989

Echinococcus multilocularis: a rare cestode of the domestic cat in France.

A cat living in the city of Annemasse (Haute-Savoie) was parasitized by a single minute specimen of the cestode E. multilocularis. The main characteristics of the parasite are described and illustrated. The cat has not previously been reported as one of the definitive hosts of this cestode in France. A potentially serious epidemiological problem is raised by the presence of an infected cat in an urban estate.

Animals↗
PubMed1989

Diagnosis of adult linear IgA dermatosis by immunoelectronmicroscopy in 16 patients with linear IgA deposits.

Homogeneous linear IgA deposits at the dermo-epidermal junction (DEJ) shown by direct immunofluorescence are characteristic of what is termed linear IgA bullous dermatosis. However, it is not yet certain that this disease constitutes an entity distinct from other subepidermal blistering diseases, especially when IgG deposits are also present. Sixty-one cases of subepidermal blistering disease in adults were therefore investigated by immunoelectron microscopy (IEM), and the 16 patients observed to have homogeneous linear IgA deposits were compared with the 45 who had no IgA but had IgG and/or C3. In 11 of the 16 patients with IgA (four of whom also had IgG), the deposits were linear and formed a mirror image pattern on each side of the lamina densa from which they were separated by a clear space. In contrast to this monomorphic IEM pattern, clinical and other laboratory findings were very heterogeneous, making exact clinical diagnosis difficult. Of the remaining five patients in this group of sixteen, three (all with both IgA and IgG) had bullous pemphigoid, epidermolysis bullosa acquisita, and cicatricial pemphigoid, respectively, on IEM and clinical investigation. In the remaining two patients (one with both IgA and IgG, and one with IgA only) the deposits were located in the lamina lucida, making precise classification impossible. None of the 45 patients with isolated IgG and/or C3 deposition displayed the mirror image pattern. We conclude that this IEM pattern may constitute a specific diagnostic criterion of linear IgA dermatosis.

Adult↗
PubMed1988

Biochemical and morphological modifications in dexamethasone-treated mouse bone marrow-derived mast cells.

Addition of 1 microM dexamethasone (DM) to bone marrow-derived mast cells (BMMC) induced a time-dependent increase in cell histamine content. The latter reached a plateau of 2.5 micrograms/1 x 10(6) cells after 11 days in culture, compared with 100 ng/1 x 10(6) for untreated BMMC. Steroids, such as beta-estradiol, androsterone, and testosterone (1 microM), did not alter the histamine content of BMMC, whereas progesterone (1 microM) induced a moderate increase. Other glucocorticosteroids also enhanced histamine content, suggesting that the observed increase was specific for glucocorticosteroid. Treatment of BMMC with 1 microM DM for 14 days inhibited the Ag-induced, IgE-mediated release of histamine, beta-hexosaminidase, platelet-activating factor-acether, LTB4, and LTC4 by 65 +/- 3%, 66 +/- 1%, 93 +/- 3%, 66 +/- 2%, and 74 +/- 10%, respectively (mean +/- 1 SD, n = 3). In contrast with untreated cells which produce less than 2 ng/1 x 10(6) cells PGD2 after Ag challenge, DM-treated BMMC generated 16.8 +/- 0.3 ng/1 x 10(6) cells PGD2. Moreover, most of DM-treated BMMC became Alcian blue+/safranin+ and by ultrastructure, exhibited numerous cytoplasmic granules filled with abundant and uniform electron-dense matrix. The present results indicate that DM-treated BMMC exhibit biochemical and functional properties different from immature untreated cells, suggesting that a maturation-like process occurred in vitro during DM treatment.

Alcian Blue↗
PubMed1988

Cantharide acantholysis: endogenous protease activation leading to desmosomal plaque dissolution.

Using a method which allowed us to study the morphological consequences of the expression and the inhibition of proteases in living tissues, we demonstrated that the primary detectable cellular event in cantharide acantholysis is the dissolution of the dense plaque, leading to the detachment of tonofilaments from desmosomes. This process is inhibited by neutral serine protease inhibitors. This suggests that the desmosome-tonofilament complex, more precisely the desmosomal dense plaque, is the primary target of activated proteases during cantharide acantholysis, and can be disrupted by a specific epidermal protease-anti protease system. Cantharide acantholysis may be useful model for studying desmosomal turnover.

Acantholysis↗
PubMed1988

Prostaglandin D2 generation in mouse bone marrow-derived mast cells exposed to dexamethasone is associated with endogenous peroxidase activity.

The appearance of fixative-sensitive peroxidase activity in the nuclear envelope and endoplasmic reticulum of bone marrow-derived mast cells (BMMC) cultured in the presence of 1 microM dexamethasone (DM) for up to 14 days and its relationship with immunologic release of prostaglandin D2 (PGD2) by these cells were studied. Endogenous peroxidase activity, previously shown as a marker of arachidonic acid metabolism in various cell types, was visualized by cell incubation in 3,3' diaminobenzidine-containing solution before glutaraldehyde fixation. PGD2 release was induced by passive sensitization of BMMC with an optimal dose of monoclonal IgE and subsequent challenge with specific a antigen. We found that 4-week-old BMMC, used as the starting population of the present study, exhibited immature morphologic features, did not present peroxidase activity when cytochemically processed, and released minute amounts of PGD2 in response to IgE-dependent stimulation. When such BMMC were exposed to DM during 24 hours, they showed aldehyde-inhibited peroxidase activity in the perinuclear envelope and a few endoplasmic reticulum segments. As compared with untreated cells, 24-hour DM-exposed BMMC released higher amounts of PGD2 upon immunologic stimulation. After an additional 14-day period of DM exposure, an intense peroxidase activity was detected in the perinuclear envelope and the endoplasmic reticulum of BMMC, which, under immunologic stimulation, released as much as 42.4 +/- 14.7 ng of PGD2/1 x 10(6) cells. Aminotriazole (20 and 50 mM) extinguished both peroxidase activity and PGD2 release from BMMC whereas indomethacin (1 microM) suppressed PGD2 production, but did not alter endogenous peroxidase activity. Previous cell fixation with glutaraldehyde totally inhibited endogenous peroxidase reaction in DM-exposed BMMC. Moreover, 14-day DM-exposed BMMC exhibited morphologic characteristics of mature mast cells and possessed alcian blue+/safranin+ granules. Therefore, the present data suggest that appearance of peroxidase activity in the nuclear envelope and the endoplasmic reticulum of DM-exposed BMMC is associated with the ability of the cells to synthetize PGD2 and appears as a cytochemical marker of the in vitro maturation of mouse bone marrow-derived mast cells.

Aldehydes↗
PubMed1988

[Gram-negative bacteria folliculitis].

Gram-negative folliculitis was first described in 1968 and had since given rise to numerous publications. To our knowledge, no case has yet been published in France, although we observed 6 of them in 12 months. Between March, 1985 and March, 1986, samples of pus for bacteriological examination were obtained from all our patients with acnea vulgaris resistant to the standard treatment (i.e. oral tetracycline combined with topical applications of tretinoin or benzoyl peroxide), thus enabling us to detect patients who had a Gram-negative bacillus (GNB) in at least one pustule. Inflammatory and painful episodes were noted in every case. Tetracyclines, initially effective, gradually lost their activity. The lesions were always limited to the face and consisted of: either superficial small pustules located in the naso-labial line and on the upper lip and chin, associated with inflammatory papulopustular lesions of the cheeks and perioral region; or deeply sited and painful nodules of the cheeks. Various GNBs of the lactose-fermenting Gram-negative rod group were isolated from the superficial lesions, and a Proteus mirabilis strain from the deep lesions. The GNB was never found in all samples but only in 1 to 3 pustules. Four patients were treated with antibiotics proved to be active in vitro against the responsible organisms, and their lesions disappeared within a fortnight. Two patients were given isotretinoin in doses of 1 mg/kg/day with a satisfactory result after 2 and 3 months respectively. The prevalence of Gram-negative folliculitis is probably underestimated. The clinical picture is stereotyped. GNBs are found in some pustules but rarely in all.(ABSTRACT TRUNCATED AT 250 WORDS)

Acne Vulgaris↗
PubMed1988

[Natural infestation of domestic cats (Felis catus L.) by Echinococcus multilocularis Leuckart, 1863 (Cestoda): first case in France detected in peri-urban area].

A minute specimen of a tapeworm from the small intestine of a domestic cat is related to Echinococcus multilocularis. The natural infestation of the cat by this species of cestode is demonstrated in France for the first time. The cat was captured in the field around buildings of the neighbourhood of Annemasse (Haute-Savoie). This case illustrates the possibility of an urban life cycle extension of alveolar echinococcosis in the permanent endemic areas of the zoonosis in France and also the eventual risks of contamination for urban dwellers by parasite eggs laying on the ground or on the carnivorous domestic animal furs.

Animals↗
PubMed1987

High-grade malignant cutaneous plasmacytoma metastatic to the central nervous system. A case report with electron microscopy, immunohistological, and neuropathological studies.

A case of high-grade malignant extramedullary plasmacytoma (EMP), unusual in its initial cutaneous localization and major involvement in the central nervous system rapidly resulting in death, is reported. Light- and electron-microscopic studies of a skin nodule revealed a high proportion of immature and mature plasmacytes. Immunohistological study revealed that both cells synthesized different amounts of a monotypic cytoplasmic kappa light chain. Neuropathological study revealed extensive infiltration of the leptomeninges and perivascular spaces as far as the deep parenchyma. In several places, effraction of vessels resulted in parenchymatous, tumor-like, plasmacytic infiltration. The findings of this case were compared with those of the few previously reported cases of EMP with initial cutaneous or intracranial localization, and with those of immunoblastic sarcoma occurring in some cases of myeloma.

Brain Neoplasms↗