The newer macrolides: azithromycin and clarithromycin.

Azithromycin and clarithromycin are two relatively new macrolide antimicrobial agents. Although azithromycin and clarithromycin are structural analogues of erythromycin, they offer distinct advantages in comparison. This article reviews the pharmacokinetics, antimicrobial activity, clinical use, and adverse affects of these antimicrobial agents.

FDA regulation of medical software.

Currently the FDA is reviewing its policy on the regulation of computer software in the medical arena. Healthcare practitioners hope that the FDA will take the least possible regulatory action required by law to fulfill its public health responsibility and will take into account the unique status of the ever-changing software industry. Innovations in telemedicine and medical informatics have yielded significant improvements in the quality and cost of healthcare, and the imposition of cumbersome regulatory requirements on the medical software industry would slow the development and introduction of medical software products.

The newer macrolides. Azithromycin and clarithromycin.

Azithromycin and clarithromycin are structural analogues of erythromycin that have similar mechanisms of action. The newer macrolides have several distinct advantages over erythromycin, including improved oral bioavailability; longer half-life, allowing once or twice daily administration; higher tissue concentrations; and fewer gastrointestinal adverse effects. Clarithromycin and azithromycin also have enhanced antimicrobial activity. The clinical efficacy of the newer macrolides has been similar to erythromycin for the treatment of upper and lower respiratory tract and skin and soft tissue infections. New therapeutic roles include the use of azithromycin for C. trachomatis infections and the inclusion of clarithromycin or azithromycin as part of therapeutic regimens for disseminated MAC infections in HIV-infected patients. Further clinical trials are needed to determine the optimal roles for and uses of these new macrolides.

Itraconazole: a new triazole antifungal agent.

The azole antifungal agents represent a major advance in the management of superficial and systemic fungal infections. Itraconazole appears to have a broad spectrum of in vitro activity and is the first azole antifungal agent to have activity against Aspergillus species. Itraconazole acts primarily by impairing the synthesis of ergosterol, resulting in a defective fungal cell membrane with altered permeability and function. It is effective for a wide variety of mycotic infections and some fungal meningeal infections. Most adverse effects have been relatively minor and do not lead to discontinuation of therapy.

Quantitative recovery, selective removal and one-step purification of human parotid and leukemic lysozymes by immunoadsorption.

Immunoadsorption affinity chromatography was used to isolate and purify human lysozyme. The immunoadsorbent was prepared by coupling sheep anti-(human leukemic lysozyme) IgG to epoxy-activated Sepharose 6B. Lyophilized parotid saliva (21) was resuspended in distilled water (325 ml, 50 mg/ml, w/v) and applied to a column which had a capacity to bind 4.25 mg human enzyme. Non-adsorbed material did not contain lysozyme, as determined by enzymatic and immunological analyses. All lysozyme activity present in the applied sample (1.97 mg) bound to and was desorbed from the column by elution with 0.2 M sodium acetate HCl buffer, pH 1.8. The isolated material was homogeneous as determined by cationic and sodium dodecyl sulfate/polyacrylamide gel electrophoresis, ultracentrifugation, amino acid and amino-terminal analyses, and immunoelectrophoretic analysis. The one-step purification procedure yielded a 1370-fold increase in specific activity. Human lysozyme was also selectively purified by this method from an ammonium sulfate precipitate of the urine of a patient with chronic monocytic leukemia. Amino acid and polyacrylamide gel electrophoretic analyses indicated that the purified enzyme was identical to human lysozyme isolated from leukemic urine by classical biochemical techniques.