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Biomedical subjects

C Merle

Publications and source records attributed to C Merle.

36 records · Page 2Linked to original sources
PubMed1999

Development of a "continuous-flow adhesion cell" for the assessment of hydrogel adhesion.

The purpose of this study was to develop an in vitro perfusion technique or "continuous-flow adhesion cell" model to predict the in vivo performances of different mucoadhesive drug delivery systems based on hydrogels. Two studies were performed, either using a rabbit small intestine or a polyethylene surface; the adhesion of four gels--two poly(acrylic acid)s (PAAs) (carbomer [CM] and polycarbophil [PC]), an ethyleneoxide-propyleneoxide block copolymer (Poloxamer 407 [PM]), and a polysaccharide (scleroglucane [SG])--were evaluated. In this respect, scleroglucane was used as a control. The adhesiveness of the different gels for both supports is in accordance with that described in the literature, that is, polycarbophil adhered more strongly than carbomer, which itself adhered more strongly than poloxamer. This study proved that the gels adhere more strongly to the polyethylene tube than to the rabbit small intestine, thus indicating that evidence for adhesion properties does not need any presence of mucus. Therefore, our in vitro model could be a good method, more precise and more simple than an ex vivo technique, to predict the bioadhesion of gelified devices.

Adhesiveness↗
PubMed1999

[Discovery of a focus of intestinal bilharziasis in te Republic of Djibouti].

An unprecedented pocket of intestinal schistosomiasis was discovered in the Republic of Djibouti in 1997. The first cases were diagnosed in French and Djiboutian tourists who presented initial symptoms of bilharzian infection after bathing in the fresh-water basin under Hassan Gari Bira Falls, near Randa. Seventeen cases were subsequently confirmed by detection of anti-schistosome antibodies using indirect hemagglutination (IH) and indirect immunofluorescence (IIF) and/or detection of Schistosoma mansoni eggs in the stool. Further testing was performed in 35 village inhabitants, mostly children, who had been exposed by bathing in the basin. The IH reaction was positive in 28 patients (80 p. 100) including 17 (49 p. 100) with levels greater than 1/64. In 92 p. 100 of cases, IH findings were confirmed by IIF which indicated that association with hypereosinophilia was common. Schistosoma mansoni eggs were found in stools from 7 patients (19 p. 100) who generally displayed mild hypereosinophilia. Information concerning the zone of risk was distributed and control measures were undertaken as widely as possible in Djibouti and abroad.

Adolescent↗
PubMed1998

In vitro influence of apatite-granule-specific area on human growth hormone loading and release.

Although calcium phosphate biomaterials often are used as drug delivery systems (DDS) at bone sites, the conditions affecting the loading of the therapeutic agent (TA) have not been well documented. A human growth hormone (hGH) adsorption method was used in this study to investigate the influence of the formulated apatite (AP)-specific area on loading and release. AP powders were formulated with a 200-500 microm granulometry and various specific areas. Two milligrams of hGH in solution were deposited for 24 h at 37 degrees C on 100 mg of AP with different specific areas. The amount of hGH loaded was determined by immunoradiometric assay (IRMA) and eluted stain bioassay (ESTA) using Nb2 lymphoma rat cells. Although loading was not greatly influenced by a specific area between 3 and 25 m2/g, dependency was noted for higher specific areas. Human GH release was measured by IRMA and ESTA over a 33-day period, with half-time release between 25 and 79 h. Comparison of IRMA and ESTA measurements for the hGH amounts loaded showed that hGH biologic activity was conserved. Results indicate that it is feasible to control the quantity of TA loading on AP by modifying specific areas for in vivo applications.

Animals↗
PubMed1998

Idiopathic hypersomnia.

Identification of idiopathic hypersomnia dates back 20 years only. It typically consists of prolonged nocturnal sleep, great difficulty waking up in the morning or at the end of a nap, and constant or recurrent excessive daytime sleepiness. Complete and incomplete forms are encountered. Twenty-three subjects fulfilling ICSD criteria are reported with clinical, polysomnographic and immunogenetic data. Considering differential diagnosis is an important step in the diagnosis of idiopathic hypersomnia. Idiopathic hypersomnia is much less frequent than narcolepsy. A strong genetic component is suggested by the high proportion of familial cases. No association with HLA has been evidenced to date.

Adolescent↗
PubMed1998

[Assessment of three filters for respiratory function tests].

Several filters specific for respiratory function tests have been on the market for several years. Recommended by the manufacturers to avoid contaminating the equipment and thus improve patient safety, these filters require a considerable financial investment. We studied the passage of diluted blood into artificial saliva in a patient model simulating inspiration tests and rapid forced expiration to assess the retention capacity of three filters used for respiratory function tests: Multi SPIRO MI-90016 (MultiSPIRO), PF 30S (Pall Biomedical) and Spirobac (Dar. S.p.A). The mean percentage of passage was 1.48% through the MI-90016 filter, 57.15% through the PF 30 S filter and 70.45% through the Spirobac filter. These findings provide further elements for choosing filters for respiratory function tests. Indeed, despite the manufacturers' commercial arguments, the technical documents provided do not give necessary information on the filtering capacity of the filters on the market. We have observed that two out of the three filters tested do no meet the standards expected by clinicians.

Blood↗
PubMed1997

Potential efficacy of a delta 5-aminolevulinic acid bioadhesive gel formulation for the photodynamic treatment of lesions of the gastrointestinal tract in mice.

A delta 5-aminolevulinic acid (ALA) bioadhesive gel has been developed and evaluated in an in-vivo mouse model for photodynamic treatment of gastric cancer or Barrett's oesophagus. Four gels were tested: noveon AA-1, keltrol T, lutrol and blanose. An initial in-vitro study of gel adhesion showed that noveon and keltrol had longer polyethylene transit times than lutrol and blanose. In-vivo assays indicated that protoporphyrin IX was synthesized by gastric mucosa when ALA-noveon and ALA-lutrol were used (preferable results for noveon). Keltrol was eliminated from the study after these investigations. Only ALA-noveon gel was retained for studies of the relationship between ALA dose and fluorescence. Fluorescence measurements in-vivo showed that ALA concentration and application time had an influence on protoporphyrin IX synthesis. Maximum intensity (2091 counts s-1) was found with 2 mg mL-1 ALA, and fluorescence intensities differed with application time, reaching 1805 counts s-1 after 240 min. ALA-noveon, showing good adhesion and enabling efficient diffusion of ALA at a pH < 6, was considered the best formulation for maintaining ALA stability.

Aminolevulinic Acid↗
PubMed1994

[Cutaneous tertiary syphilis with neurological symptoms].

INTRODUCTION: The tertiary cutaneous syphilis is now extremely rare. We report a case of tubercular cutaneous syphilis associated with neurological dysfunction. We emphasize the difficulties to interpret serologic and CSF tests for the diagnosis of neurosyphilis. CASE REPORT: A 63 year-old-woman had nodular, purplish and painless cutaneous lesions on forehead and forearm for 6 months. The biopsy showed a dermohypodermic lymphoplasmocytic granuloma, without necrosis, with endothelitis. Syphilis serologic tests were positive: VDRL = 512 U; TPHA = 40,960 U; FTA abs: IgG = 72,000 U; IgM = 1,350 U; Nelson test = 100 p. 100 (1,200 U). HIV test was negative. There was a past history of a positive syphilis serologic test when the patient was 20-year-old. The patient complained of shaking and her family spoke of gradual mental deterioration and behaviour troubles. The neurological examination showed a major frontal syndrome, cerebellar dysfunction with dysarthria and a major labial and lingual tremor. There is no lymphocytosis nor increased protein in the CSF; VDRL test was negative, TPHA test was positive, FTA abs = 4,000 U (IgG), and TPHA was increased. Penicillin G 16 millions units/day was given intravenously for 20 days; a slow increase was made in association with steroids at the beginning. The cutaneous lesions regressed in 14 days, but the neurologic state did not change. Six months later, there was still no IgM, TPHA decreased and VDRL was unchanged. DISCUSSION: While the diagnosis of tertiary cutaneous syphilis was correct, the neurological abnormalities are difficult to classify. The symptoms were those of general paresis, but there is no argument favouring biological CSF activity (no increase in protein or lymphocytosis, negative VDRL). Nevertheless, in the context of very positive serologic tests and tertiary cutaneous syphilis, we treated this case as a neurological syphilis. The treatment regimen and the need of current cures are still under discussion.

Facial Dermatoses↗
PubMed1993

[Anogenital papillomavirus lesions in humans with or without HIV infection. Comparison of colposcopic, histopathological and virological results].

Anal and genital lesions caused by human papilloma virus (HPV) may be associated with severe dysplasia and cancer, chiefly in cases of "high risk" HPV types 16, 18, 31, 35, 51. The frequency of HPV infections and the severity of genital cancers seem to be increased in patients with human immunodeficiency virus (HIV) infection. PATIENTS AND METHOD. The distribution of different HPV types was compared with the anatomical and clinical features of the lesions in two populations, one HIV+ (n = 40) and the other HIV- (n = 48), who had anal and genital lesions. The HPV DNA was determined by molecular hybridization in situ, using biotinylated probes which recognized HPV types 6/11, 16/8 and 31/35/51 on 99 lesions. RESULTS. HIV+ subjects differed from HIV- subjects in that a higher proportion of them had anal lesions (50 p. 100 vs 10 p. 100) and condyloma latum (80 p. 100 vs 50 p. 100). Koilocytosis without dysplasia was more often found in HIV- subjects (12.5 p. 100 vs 55 p. 100). Conversely, dysplasia was more frequent among the lesions of HIV+ subjects: grade I 39.5 p. 100 vs 17.5 p. 100; grade II 25 p. 100 vs 4 p. 100; grade III 12.5 p. 100 vs 0 p. 100. Koilocytosis was preferentially associated with condyloma acuminatum. In HIV+ subjects the DNA of HPV, detected in 73 p. 100 of the lesions, was "high risk" HPV DNA in 86 p. 100 of the cases, whereas in HIV- subjects 51 p. 100 of the samples were positive in hybridization, and 61.5 p. 100 had "low risk" HPV DNA. In subjects of all groups "high risk" HPV was found in dysplastic lesions. CONCLUSION. HIV seropositive subjects show an imbalanced distribution of HPV with predominance of "high risk" HPV. This suggests that immunodepression encourages infection by this oncogenic virus, thereby contributing to the frequency of cancer in HIV+ subjects.

AIDS-Related Opportunistic Infections↗
PubMed1990

Intractable epidermolysis bullosa acquisita: efficacy of cyclosporin A.

We report the case of a 66-year-old man who presented with a spontaneous blistering involving both skin and mucous membranes, diagnosed as an inflammatory form of epidermolysis bullosa acquisita. During a 5-year course, the condition failed to respond to various therapies. Finally, only ciclosporin, together with a low dose regimen of prednisone, achieved a dramatic improvement with a total clearing within 6 months, persisting 1 1/2 years after discontinuation. Such results prompt us to propose such an association as a primary therapeutic scheme in an otherwise barely tractable disease.

Aged↗