Economic analysis of antibiotic regimens used in the treatment pharyngitis: a prospective comparison of azithromycin versus roxithromycin.

The economic impacts in terms of cost and effectiveness (speed of resolution of symptoms) of 3- and 5-day courses of azithromycin and a 10-day course of roxithromycin were compared in a randomized, open study in patients with symptoms suggestive of beta-haemolytic streptococcal pharyngitis. Direct medical costs and absence from work were recorded and symptom scores and compliance were used to assess the effectiveness of therapies. Although no differences between treatment groups in terms of overall clinical response rates were detected 2 and 4 weeks after the start of treatment, more rapid resolution of symptoms was achieved with 3- and 5-day courses of azithromycin than with a 10-day course of roxithromycin. There was also a significant reduction in the time absent from work in the azithromycin treatment groups. The total costs of care over the 4-week evaluation period were lower for the 3- and 5-day azithromycin courses (US$193.60 and US$195.30 respectively) than for roxithromycin (US$202.10). The major cost components were absence from work (58.6%), visits to the physician (15.3%) and utilization of antibiotics (14.9%). Compliance was significantly better (P < 0.01) in patients prescribed azithromycin for 3 and 5 days (58.0% and 42.9% respectively) than in those who received roxithromycin (20.3%) and a significantly longer symptom-free period (P < 0.01) was reported in azithromycin- compared with roxithromycin-treated patients. These findings support the hypothesis that a 3- or 5-day course of azithromycin is as effective as a 10 day course of roxithromycin in the treatment of patients with pharyngitis and is associated with lower costs. Furthermore, azithromycin is associated with faster resolution of symptoms and improved patient compliance.

Interaction of macrolides with alpha dornase during DNA hydrolysis.

Since patients with cystic fibrosis are often treated with alpha dornase to reduce sputum viscosity, and because of preliminary reports of efficacy of long-term low-dose erythromycin therapy in chronic airway diseases, it is likely that alpha dornase and macrolides might be given together in such patients. A possible interaction between these drugs was therefore investigated. Using hyperchromic effect to quantify alpha dornase activity, a time- and dose-dependent inhibitory effect on human DNA hydrolysis has been observed for erythromycin, roxithromycin and azithromycin. Inhibitory doses 50% for alpha dornase were graphically determined. Azithromycin exhibited the strongest inhibitory effect.

[Azithromycin and genital infections]. / Azithromycine et infections de la sphère génitale.

The lower genital tract infections due to Chlamydia trachomatis are frequent, essentially occurring in young patients, with possible complications and severe sequela, particularly in women where the sterility risk is one of the major consequences. If an effective treatment could be systematically proposed, a good compliance (easy administration and good toleration) is one of the key factor to success. In this context, the azithromycin displays numerous advantages. The azithromycin in vitro activity on Chl. trachomatis strains is permanent with MIC comprised between 0.06 and 0.125 micrograms/ml, with an activity equivalent to those of other macrolides, to tetracyclines and quinolones. Different animal models allow to demonstrate the curative activity of the azithromycin administered as a single dose, at dosage regimen equivalent to those used in man, and a prophylactic activity on the salpingitis onset in provoked Chl. trachomatis infections. Several comparative clinical studies with azithromycin administered as a 1 g single dose displayed very satisfactory results with 98% of bacterial eradication, identical to those obtained with reference treatment. On the other hand, restrictions to the product use are a less constant activity against Neisseria gonorrhoeae and a lack of efficacy on Mycoplasma hominis. The efficacy on Treponema pallidum remains to be clinically tested.

Preferential V delta 1 expression among TcR gamma/delta-bearing T cells in human oral epithelium.

The oral cavity is a septic area colonized by various bacterial species, and the oral mucosa is frequently submitted to microtraumas. Several mechanisms are implicated in the defence of the oral tissue, but little is known concerning the eventual presence and role of gamma/delta T cells at this site. Samples of healthy keratinized oral mucosa were examined with immunochemical techniques using anti-CD3, CD4, CD8, CD22, TcR delta 1, V delta 1 and V delta 2 monoclonal antibodies. Whatever the site examined, gamma/delta T cells represent at most 2% of the T-cell population, a value similar to that found in other tissues. In the connective tissue, under the basement membrane, V delta 2+ gamma/delta T cells are predominant whereas the epithelium mostly contains V delta 1+ gamma/delta T cells. The significance of this preferential V delta 1 intraepithelial presence is discussed.

Co-selection of the rare T cell receptor-gamma B haplotype in mouse lines selected for low responsiveness to red blood cell antigens.

T cell receptor (TcR)-gamma haplotype was investigated in seven pairs of murine Biozzi lines selected for low and high antibody (Ab) response to different antigens (Ag). High-responder lines (H) express gamma A or gamma C haplotypes irrespective of the selecting Ag. In contrast, the gamma B haplotype, which is rare in laboratory mouse strains, is found in all low-responder lines (L) to sheep erythrocyte Ag (SE). However, the TcR-gamma B locus might only have a low penetrance in the control of the SE response. Moreover, investigations using LIVA mice, which were selected for low SE response from homozygous gamma A founder parents, indicate that the gamma B haplotype is neither necessary nor sufficient to achieve a low-responder phenotype. The gamma B haplotype might, thus, be co-selected to confer to L mice an improved resistance to bacterial infections mediated by gamma delta T cells compensating the profound and nonspecific immune perturbation associated with the low Ab response.

New T-cell receptor gamma haplotypes in wild mice and evidence for limited Tcrg-V gene polymorphism.

Tcrg gene polymorphism was investigated by Southern blot analysis on a panel of laboratory and wild mouse strains using a set of probes which identify all known Tcrg-V and -C genes. Only three haplotypes are found in laboratory mice: gA, gB, and gC which are represented by BALB/c, AKR, and DBA/2 prototypes respectively. gA and gC haplotypes are the most frequent among laboratory mice whereas gB is poorly represented. Seven new haplotypes are described among 23 wild mice corresponding to four Mus musculus subspecies (Mus mus domesticus, castaneus, musculus, and molossinus). However, only a few new alleles of individual genes are observed. Tcrg-V genes located at the 5' end of the Tcrg locus (V7 and V4) appear to be nonpolymorphic whereas two Tcrg-V3, -V5, -V6, -C4 and three Tcrg-V1, -V2, -C1, -C2, and -C3 specific restriction fragment length polymorphisms are detected. These results indicate a relatively high degree of conservation of Tcrg genes as compared to other members of the immunoglogulin (Ig) gene family and might be related to the specifity and function of gamma delta T cells. Several of the new haplotypes described here result from point mutations in noncoding Tcrg-V or -C gene-flanking regions. Recombinations may have also participated in the evolution of the Tcrg locus. Finally, these new Tcrg haplotypes are unequally distributed among the four M. m. subspecies and support the idea that the gA and gC haplotypes found in laboratory mice are inherited from M. m. domesticus whereas gB might originate from asian subspecies (castaneus, musculus or molossinus).