Entropy-driven formation of the gyroid cubic phase.

We show, by computer simulation, that tapered or pear-shaped particles, interacting through purely repulsive interactions, can freely self-assemble to form the three-dimensionally periodic, gyroid cubic phase. The Ia3d gyroid cubic phase is formed by these particles on both compression of an isotropic configuration and expansion of a smectic A bilayer arrangement. For the latter case, it is possible to identify the steps by which the topological transformation from nonintersecting planes to fully interpenetrating, periodic networks takes place.

Content and accuracy of abstracting services: clinical perspective.

Abstracts in Inpharma, deHaen Drugs-in-Use, International Pharmaceutical Abstracts (IPA), Reactions, and Clin-Alert were evaluated using the number of omissions and errors as endpoints. Fifty-one abstracts were compared with original articles by pharmacy students using a standardized checklist for drug therapy and adverse drug reaction articles. The overall omission rate per abstract was 3.2 +/- 2.5. There were no significant differences in omission rates in drug therapy abstracts between Inpharma, deHaen, or IPA abstracting services. For adverse drug reaction abstracts, IPA had significantly more omissions than Clin-Alert (p less than 0.001) and Reactions (p less than 0.01). One error occurred in approximately every fifth abstract. No differences were shown between abstracting services in this regard. Although abstracts and abstracting services can provide useful information--particularly when information is needed in a timely fashion, when an original article is difficult to obtain, or when written in a foreign language--they should not be considered a consistently reliable source of information upon which to base decisions, as evidenced by the number and types of omissions and errors described in this study.

Norfloxacin: clinical pharmacology and clinical use.

Norfloxacin, a nalidixic acid analog, is the first of the fluorinated quinolinecarboxylic acids to be marketed in the United States. It demonstrates potent antibacterial activity against aerobic, gram-negative bacteria including the Enterobacteriaceae, gentamicin-resistant Pseudomonas aeruginosa, and penicillin-resistant Neisseria gonorrhoeae. Norfloxacin exhibits good activity against methicillin-resistant and -sensitive Staphylococcus aureus, but less activity against most other aerobic, gram-positive organisms. Anaerobic bacteria are resistant to the drug. Resistance to norfloxacin is not plasmid mediated, but is secondary to bacterial mutation, and occurs less frequently than nalidixic acid resistance. Its pharmacokinetic properties after a 400-mg oral dose consist of a peak serum concentration of 1.3-1.58 micrograms/ml, an elimination half-life of 3-7 hours, and good penetration into kidney and prostatic tissues. Renal excretion is the major route of elimination. Norfloxacin is highly effective in the treatment of uncomplicated and complicated urinary tract infections, and gonococcal urethritis. Adverse effects are generally well tolerated and usually do not require discontinuation of therapy.

Program coordinated by a drug information service to improve adverse drug reaction reporting in a hospital.

A program coordinated by a drug information service to improve adverse drug reaction (ADR) reporting in a hospital is described. At a 520-bed teaching hospital, the drug information service was asked to design a new adverse drug reaction reporting system that would encourage clinicians to report ADRs. A new system was implemented on a general medical unit: A physician, pharmacist, or nurse telephoned the drug information service when an adverse drug reaction was suspected, and drug information personnel followed up on the report, completing all subsequent investigation and documentation. A standard algorithm was used to evaluate causality of the reported reactions. Pertinent data were entered on a form and retained in the drug information service. The primary physician's approval was obtained before a reaction could be reported on an FDA drug-experience form. Drug information service personnel reviewed the ADR data monthly to detect any trends that clinicians should be aware of and to prepare a report for the pharmacy and therapeutics committee. Nurses, physicians, and pharmacy personnel were oriented to the new system before its implementation and were subsequently informed about reported ADRs and use of the system through newsletters and meetings. In the initial three-month period, 23 ADRs involving 19 drugs were reported from the medical unit; in a six-month period before development of the new system, no ADRs had been reported. This ADR reporting system developed and implemented by the drug information service was effective in improving reporting of adverse drug reactions.

Comparison of three algorithms used to evaluate adverse drug reactions.

The consistency of three algorithms in evaluating adverse drug reactions (ADRs) was studied. As part of a hospital's ADR protocol, doctor of pharmacy students were required to collect and summarize all ADR data. Algorithms by Kramer, Naranjo, and Jones were used to evaluate all ADRs between January and May 1984. Kramer's algorithm was used for every reported ADR; Naranjo's and Jones' algorithms were used to check consistency in scoring among ADRs already scored with the Kramer algorithm. The two numerical scales (Kramer and Naranjo) were compared using linear regression. The results of all three algorithms were translated into categories of suspicion (A = definite or probable; B = probable; C = possible; and D = unlikely, doubtful, or remote) and evaluated for consistency with a weighted kappa (kw) statistical test. A total of 28 ADRs were evaluated, and the correlation (r = 0.87) between the total numerical scores of the Kramer and Naranjo algorithms was significant. Comparison of the Kramer and Naranjo algorithms showed 67% agreement with a kw value of 0.43 (-1 = perfect disagreement and +1 = perfect agreement). Similarly, there was 67% agreement (kw = 0.48) between Kramer's algorithm and Jones' algorithm. Agreement between Naranjo's and Jones's algorithms was 64%, but the kw value was only 0.28. The simpler and less time-consuming Naranjo algorithm compared favorably with the Kramer algorithm in scoring ADRs; more data are needed to support the use of the Jones algorithm.