Short-duration topical treatment of tinea pedis using terbinafine emulsion gel: results of a dose-ranging clinical trial

BACKGROUND

In the treatment of tinea pedis, current terbinafine formulations are applied once or twice daily for 7 days. A terbinafine emulsion gel formulation has been developed to provide a 5-day treatment course for tinea pedis.

OBJECTIVE

To determine the lowest effective concentration of terbinafine (1% or 3%) emulsion gel applied once daily for 5 days for the treatment of tinea pedis.

METHODS

This double-blind, placebo-controlled study evaluated the efficacy of 1% and 3% terbinafine gel for 5 days in 84 outpatients with tinea pedis. The primary efficacy endpoint was the percentage of patients with effective treatment (negative microscopy and culture with only mild erythema/desquamation/pruritus [total score<or=2]) at study endpoint (last post-baseline observation up to and including week 6).

RESULTS

Efficacy rates with terbinafine 1% and 3% emulsion gel were significantly higher than with placebo (86% and 68% vs 11%, respectively; p<0.001). Similarly, mycological cure rates were significantly greater with terbinafine 1% and 3% gel (97% and 89%, respectively) than with placebo (22%; p<0.001).

CONCLUSIONS

Terbinafine 1% emulsion gel used once daily for 5 days was the lowest effective concentration, and was significantly superior to placebo. Both concentrations were effective and safe, providing convenient, short-duration treatment of tinea pedis.

Antigenic and genetic evolution of swine influenza A (H3N2) viruses in Europe

In the early 1970s, a human influenza A/Port Chalmers/1/73 (H3N2)-like virus colonized the European swine population. Analyses of swine influenza A (H3N2) viruses isolated in The Netherlands and Belgium revealed that in the early 1990s, antigenic drift had occurred, away from A/Port Chalmers/1/73, the strain commonly used in influenza vaccines for pigs. Here we show that Italian swine influenza A (H3N2) viruses displayed antigenic and genetic changes similar to those observed in Northern European viruses in the same period. We used antigenic cartography methods for quantitative analyses of the antigenic evolution of European swine H3N2 viruses and observed a clustered virus evolution as seen for human viruses. Although the antigenic drift of swine and human H3N2 viruses has followed distinct evolutionary paths, potential cluster-differentiating amino acid substitutions in the influenza virus surface protein hemagglutinin (HA) were in part the same. The antigenic evolution of swine viruses occurred at a rate approximately six times slower than the rate in human viruses, even though the rates of genetic evolution of the HA at the nucleotide and amino acid level were similar for human and swine H3N2 viruses. Continuous monitoring of antigenic changes is recommended to give a first indication as to whether vaccine strains may need updating. Our data suggest that humoral immunity in the population plays a smaller role in the evolutionary selection processes of swine H3N2 viruses than in human H3N2 viruses.

A call to restructure the drug development process: government over-regulation and non-innovative late stage (Phase III) clinical trials are major obstacles to advances in health care

The history of drug/vaccine development has included major advances guided primarily by risk/benefit analyses concerning the innovative agent, not by evidence-based clinical trials (Phase I-IV). Because the approval for new drugs is hindered under the present process, the system requires restructuring. The Phase I/II study period should be more flexible, using the "environment of knowledge" about the new agent, plus risk/benefit assessments. Phase III, as presently constructed, does not add new adverse events data, it provides a narrower profile of drug efficacy than properly done Phase II studies, and placebo-controlled trials continue to raise unresolved ethical and social issues. Phase III studies should be abandoned for most drugs, and substituted with properly powered Phase II dose-ranging studies plus careful post-marketing surveillance. Phase III should be a penalty for poor drug development, not a regulatory requirement. To accomplish efficient drug development, greater cooperation between pharmaceutical companies and governments in developing clinical trials is needed rather than over-regulation. These changes will synchronize the drug development and regulatory process with the current rapid drug discovery process, reduce drug development time and cost, and improve patient care.

Cough and fear of sleep: early clinical signs of Bordetella pertussis in an adult

Pertussis is increasing in frequency among adults, but early diagnosis requires special attention to details in the medical history. We describe a 64 year-old male with classic signs and symptoms of pertussis and documented Bordetella pertussis infection that were overlooked because he presented with a chief complaint of cough and fear of falling asleep. Coughing paroxysms and a feeling of suffocation (30-60 seconds) only occurred at night after short periods of deep sleep (30-45 minutes). The physicians did not observe these episodes during daytime examinations, and the basis of the patient's fear of sleep was not explored. We recommend reassessment of how adults describe symptoms of pertussis, including fear of sleep, and we suggest the use of PCR technology to allow early diagnosis and prompt treatment.

High gene flow levels lead to gamete wastage in a desert spider system

Field censuses, breeding experiments, and a quantitative model are used to obtain insight into the extent and consequences of genetic mixing between locally adapted populations of a desert spider. Typically, 9% of the matings of desert riparian spiders (non-aggressive phenotype) in native habitat involve an arid-land partner (aggressive phenotype). Mating was found to be random with respect to behavioral phenotype, but linearly related to both the rate of immigration and survival of immigrants from surrounding arid habitats in the riparian area. Genetic mixing between riparian and arid-land spiders produces offspring that exhibit lower rates of survival in riparian habitat. Two extreme behavioral phenotypes were also observed in the field studies: approximately 5% of the female spiders attacked all males they encountered while another 22% ran from all potential mates. Punnett square analyses of the potential genotypes produced by introgression between arid- and riparian-adapted spiders indicate that these extreme phenotypes appear in F2 generation hybrids and backcrosses. Because there is a costly wastage of gametes in the case of mixed phenotype mating, model results indicate that within three generations of the cessation of gene flow, the riparian population would be free of mixed genotypes and moving towards genetic differentiation.

Retrieval success is accompanied by enhanced activation in anterior prefrontal cortex during recognition memory: an event-related fMRI study

Neural regions associated with retrieval success were identified using event-related fMRI procedures and randomly ordered trials on a recognition memory test. Differences between hits and correct rejections (CRs) occurred multiple regions, including bilateral anterior and right dorsolateral prefrontal cortex, bilateral inferior parietal cortex, and right superior parietal cortex (all hits > CRs), and right occipital cortex (CRs > hits). The hit > CR pattern is not compromised by time-on-task explanations because response latencies for correctly rejected words exceeded those for hits. Converging evidence for the claim that the hit > CR pattern identified neural correlates of retrieval success was obtained by unconfounding item history and retrieval success. That is, we implemented a third condition in which nonstudied words were presented, yet retrieval success was hypothesized to facilitate CRs of these lures. Specifically, in when confronted with a familiar, yet nonstudied word, (e.g., nosedive after studying nosebleed and skydive), subjects might adopt a strategy whereby they recall the studied word(s) that gave rise to the familiarity (nosebleed, skydive) and thereby reject the lure. This method of instantiating retrieval success under conditions in which the target word had not been studied offers converging evidence for the claim that anterior-prefrontal cortex (among other regions) demonstrates enhanced activation during retrieval success.

Extra-pair paternity in waved albatrosses

We estimated the rate of extra-pair fertilizations (EPFs) in waved albatrosses (Phoebastria irrorata) on Isla Española, Galápagos, Ecuador, using multilocus minisatellite DNA fingerprinting. Waved albatrosses are socially monogamous, long-lived seabirds whose main population is on Española. Aggressive extra-pair copulation (EPC) attempts have been observed in the breeding colony during the days preceding egg-laying. Our genetic analyses of 16 families (single chicks and their attending parents) revealed evidence of EPFs in four families. In all cases males were the excluded parent. These data suggest that waved albatrosses have an unusually high rate of EPF relative to taxa with similar life histories. Future behavioural observations will determine the extent to which forced vs. unforced EPCs contribute to this high EPF rate.

Considerations regarding mass vaccination against typhoid fever as an adjunct to sanitation and public health measures: potential use in an epidemic in Tajikistan

We report on the ongoing epidemic of typhoid fever in Tajikistan that started in 1996. It has involved more than 24,000 cases to date, and is characterized by multiple point sources, overflow of sewage, contaminated municipal water, and person-to-person spread. Of the Salmonella typhi isolates available for testing in western laboratories, more than 90% are multidrug-resistant (MDR). Most recently, 28 (82%) of 34 isolates are resistant to ciprofloxacin, representing the first reported epidemic of quinolone-resistant typhoid fever. In the past, mass immunization during typhoid fever epidemics has been discouraged. A review of this policy is recommended in light of the alarming emergence of quinolone-resistant strains of S. typhi, the availability of improved vaccines, and the ongoing epidemic in Tajikistan. Mass immunization may be a useful measure for the control of prolonged MDR typhoid fever epidemics, as an adjunct to correction of municipal infrastructure and public health intervention.

Use of granulocyte-macrophage colony stimulating factor in the treatment of prolonged haematopoietic dysfunction after chemotherapy alone or chemotherapy plus bone marrow transplantation

This study evaluates the use of granulocyte-macrophage colony stimulating factor (GM-CSF) in patients with prolonged haematopoietic dysfunction (> 21 days) after using chemotherapy to treat cancer. One hundred and seven patients were identified who had a leucocyte count below 1000 cells/mm3 more than 21 days after start of chemotherapy (81 patients) or after bone marrow transplantation (BMT)(26 patients). There were 66 males and 40 females ranging in age from 4.5 to 82 years. The duration of aplasia was 48 +/- 43 days in the chemotherapy alone group, and 79 +/- 57 days in the post BMT group. Over 80% of the patients had haematologic malignancies and 70% had an infection prior to the start of the cytokine. Patients received 5 micrograms GM-CSF/kg1 body weight daily i.v. or s.c. for 14 +/- 11 days in the chemotherapy group and 20 +/- 26 days in the BMT group. Sixty percent of chemotherapy patients and 58% of BMT patients had a haematological response to treatment (leucocyte count > 2000 cells/mm3. Median times to haematologic recovery were 7 days in the chemotherapy group and 10 days in the BMT group. There was a significant reduction in the number of infections (73% to 28% in the chemotherapy group). Clinical responses in the two groups were 55% and 50%, respectively. No severe, drug-related adverse events were reported and no evidence of stimulation of malignant clones was observed. It is concluded that GM-CSF is effective and well tolerated in patients with prolonged bone marrow dysfunction after chemotherapy or BMT. Although results from an open-label trial must be viewed with caution, this observation confirms the value and safety of GM-CSF therapy in patients with this severe, and often fatal, condition.

Evaluation of 6 weeks treatment of terbinafine in tinea unguium in a double-blind trial comparing 6 and 12 weeks therapy. The Lagos V Study Group

Terbinafine (Lamisil) has been registered throughout the world for the treatment of finger and toenail onychomycosis. The recommended duration of treatment of toenail onychomycosis based on phase III studies is 12 weeks. This study was designed to determine: (i) if patients in whom the proximal part of the toenails was not affected respond as well after 6 weeks treatment as after 12 weeks treatment; (ii) to identify factors which may allow selection of patients for shorter treatment duration; and (iii) confirm that 6 weeks therapy is sufficient in fingernail mycosis. One hundred and forty-eight patients received 250 mg terbinafine daily for either 6 or 12 weeks in a double-blinded manner, and were allowed until 48 weeks after start of therapy. Cure of the nail infection was defined as negative mycological tests (mycological cure) and progressive growth of normal nail (clinical cure). Mycological cure was recorded in 43 of 72 (59.7%) in the 6-week group and 55 of 76 (72.4%) in the 12-week group. In those who completed the study per protocol in the 6-week group, 34 of 61 (55.7%) were cured mycologically corresponding to 46 of 56 (82.1%) in the 12-week group. The overall clinical and mycological cure rates for the two groups were 28 of 61 (45.9%) and 33 of 56 (58.9%), respectively. In the small number of patients with associated fingernail infection, all were improved and six of eight (75.0%) were cured after a duration of treatment of 6 weeks. A priori risk factors for failure of cure could not be identified in either group. However, shorter duration of disease prior to treatment and no involvement of the big toenail was associated with a trend toward better responses in both groups. It can be concluded from this study that, in toenail mycosis without visible matrix involvement, 6 weeks treatment of terbinafine is generally not sufficient, whereas fingernail infections respond well to this short therapy.

Collaborative teaching. A strategy for interactive telecourses

The use of telecommunication technology in nursing education is increasing dramatically. Interactive television courses are effective and efficient in overcoming barriers of distance and access. Faculty members using the technology find many opportunities for innovation and creativity as courses are implemented. The authors describe a nursing graduate course offered collaboratively between two schools of nursing.

Evaluation of tolerability and antibody response after recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) and a single dose of recombinant hepatitis B vaccine

Recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) has been shown to augment antigen presentation by macrophages and dendritic cells in vitro, and to increase antibody responses to injected antigens in experimental animals. To evaluate the usefulness of rhGM-CSF as a vaccine adjuvant, 108 healthy volunteers were randomly assigned to receive an injection of rhGM-CSF (n = 81) or placebo (control group; n = 27), followed by an injection with recombinant hepatitis B vaccine into the same site. During the study period of 28 days, protective antibody titers to hepatitis surface antigen (anti-HBs10 mIU ml-1) were observed in 11 of 81 subjects receiving rhGM-CSF, but in none of the controls (P = 0.035). Injections were well tolerated. A single i.m. or s.c. injection of 20-40 micrograms of rhGM-CSF significantly enhances antibody responses when given at the same site as recombinant hepatitis B vaccination.