Biomedical subjects

Michel Cormier

Publications and source records attributed to Michel Cormier.

5 recordsLinked to original sources

PubMed2004

Transdermal delivery of desmopressin using a coated microneedle array patch system.

Desmopressin is a synthetic peptide hormone chiefly used for treatment of enuresis in young children. It is available in injectable, intranasal, and oral formulations. While administration by injection is poorly suited for routine use in young children, intranasal and oral administration result in low and variable bioavailability. This study therefore explored the feasibility of administering desmopressin transdermally using Macroflux technology, which uses a microneedle array to overcome the skin barrier. The tips of microneedles in 2-cm2 arrays were covered with a solid coating of various amounts of desmopressin and applied to the skin of hairless guinea pigs for 5 or 15 min. Pharmacologically relevant amounts of desmopressin were delivered after 5 min. Bioavailability was as high as 85% and showed acceptable variability (30%). Immunoreactive serum desmopressin reached peak levels after a Tmax of 60 min. Elimination kinetics for serum desmopressin was similar after transdermal and intravenous (IV) delivery, suggesting the absence of a skin depot. Only 10% of the desmopressin dose loaded onto the microneedle array was found on the skin surface after application. Additionally, the patches were well tolerated. These results suggest that transdermal delivery of desmopressin by Macroflux is a safe and efficient alternative to currently available routes of administration.

Administration, Cutaneous↗

PubMed2004

Genetic analysis of an ambler class A extended-spectrum beta-lactamase from Capnocytophaga ochracea.

A beta-lactamase gene (cfxA3, 966 bp) was isolated from a beta-lactam-resistant Capnocytophaga ochracea clinical isolate and amplified using primers from the cfxA gene of Bacteroides vulgatus. The MICs of third-generation cephalosporins were much higher than those of the transconjugant Escherichia coli strain. The deduced protein sequence, by comparison with CfxA2 of Prevotella intermedia, had a Y239D substitution and possessed the characteristics of a class A, group 2e beta-lactamase.

Amino Acid Substitution↗

PubMed2003

Microbiology of mandibular third molar pericoronitis: incidence of beta-lactamase-producing bacteria.

OBJECTIVES: The purpose of this study was to evaluate the predominant flora associated with pericoronitis in third molars and to investigate the presence of beta-lactamase-producing strains. STUDY DESIGN: The third molars in 26 adults were evaluated by cultures with nonselective media and with selective media containing amoxicillin, pristinamycin, spiramycin, metronidazole, and spiramycin plus metronidazole. RESULTS: In the majority of cases (19/26), the flora found in an anaerobic atmosphere predominated. Obligate anaerobes were present in 21 of the 26 samples. The bacteria most commonly detected were alpha-hemolytic streptococci (26/26) and the genera Prevotella (15/26), Veillonella (15/26), Bacteroides (9/26), and Capnocytophaga (9/26). Amoxicillin and pristinamycin were the most active in reducing the anaerobic cultivable counts. beta-Lactamase-producing strains were detected in 9 samples and were mostly bacteria of the genera Prevotella, Staphylococcus, and Bacteroides. CONCLUSIONS: These results highlight (1) the diversity of the microflora associated with pericoronitis and the importance of the anaerobic flora and (2) the existence of selection pressure related to the use of beta-lactams that may culminate in failure of prescribed penicillins.

Adolescent↗

PubMed2003

Evaluation of the mandibular third molar pericoronitis flora and its susceptibility to different antibiotics prescribed in france.

This work assessed the polymicrobial flora of mandibular third molar pericoronitis. Obligate anaerobes were found in almost all cases (32 of 35). Amoxicillin and pristinamycin were the most effective against the flora, particularly aerobic organisms. Metronidazole alone or combined with spiramycin was the most effective drug against obligate anaerobes.

Anti-Bacterial Agents↗

PubMed2002

Macroflux microprojection array patch technology: a new and efficient approach for intracutaneous immunization.

PURPOSE: We evaluated the Macroflux microprojection array patch technology as a novel system for intracutaneous delivery of protein antigens. METHODS: Macroflux microprojection array systems (330-microm micro-projection length, 190 microprojections/cm2, 1- and 2-cm2 area) were coated with a model protein antigen, ovalbumin (OVA), to produce a dry-film coating. After system application, microprojection penetration depth, OVA delivery, and comparative immune responses were evaluated in a hairless guinea pig model. RESULTS: Macroflux microprojections penetrated into hairless guinea pig skin at an average depth of 100 microm with no projections deeper than 300 microm. Doses of I to 80 microg of OVA were delivered via 1- or 2-cm2 systems by varying the coating solution concentration and wearing time. Delivery rates were as high as 20 microg in 5 s. In a prime and boost dose immune response study, OVA-coated Macroflux was most comparable to equivalent doses injected intradermally. Higher antibody titers were observed when OVA was administered with the microprojection array or intradermally at low doses (1 and 5 microg). Macroflux administration at 1- and 5-microg doses gave immune responses up to 50-fold greater than that observed after the same subcutaneous or intramuscular dose. Dry coating an adjuvant, glucosaminyl muramyl dipeptide, with OVA on the Macroflux resulted in augmented antibody responses. CONCLUSIONS: Macroflux skin patch technology provides rapid and reproducible intracutaneous administration of dry-coated antigen. The depth of skin penetration targets skin immune cells; the quantity of antigen delivered can be controlled by formulation, patch wearing time, and system size. This novel needle-free patch technology may ultimately have broad applications for a wide variety of therapeutic vaccines to improve efficacy and convenience of use.

Administration, Cutaneous↗