Biomedical subjects
Publications and source records attributed to K A Arndt.
Calcipotriene ointment has recently been approved for the treatment of moderate plaque psoriasis. Recent laser developments have created new and effective treatments for a variety of cutaneous pigmented disorders. Three new systemic fungicidal drugs have been developed in the treatment of tinea unguium.
BACKGROUND: Despite good results in the treatment of most port-wine stains (PWS) with continuous-wave visible-light lasers, light PWS and those in certain locations respond less favorably and have a higher risk of scarring. Robotized scanning devices such as the Hexascan device have been developed for continuous-wave laser sources to produce greater target specificity, to increase reproducibility of results, and to decrease the incidence of adverse effects. OBJECTIVE: The purpose of this study was to compare the effects of the same wavelength of light (585 nm) on test sites within PWS with the flashlamp-pumped pulsed dye laser and a continuous-wave tunable dye laser scanned through a Hexascan robotized scanning device. METHODS: Two adjacent, noncontiguous sites within PWS were treated in 29 patients, one site with the flashlamp-pumped pulsed dye laser and the other with an argon-pumped continuous-wave tunable dye laser affixed to a Hexascan device. RESULTS: Twenty-eight patients completed the study. The pulsed dye laser was found to be superior to the continuous-wave dye laser with the Hexascan device in 45% of patients, whereas the continuous-wave tunable dye laser with the Hexascan device was considered superior in 15%. There was no difference in the remaining 40%. Undesirable side effects were infrequent with both treatments. There was no significant difference in hypopigmentation or atrophic and hypertrophic scarring, but hyperpigmentation was more frequent with the continuous-wave dye laser with the Hexascan device. CONCLUSION: Both the pulsed dye laser and continuous tunable-wave dye laser with the Hexascan device produce slight lightening after one treatment. The pulsed dye laser produces slightly greater lightening than the continuous-wave tunable dye laser with the Hexascan device 6 weeks after treatment of test areas within PWS in 40% of those treated. It also produced slightly less hypopigmentation and hyperpigmentation.
As the scientific literature continues to burgeon, readers must develop strategies to efficiently glean important information from the thousands of journals published each month. Citation data can provide quantitative estimates of a journal's usefulness to the scientific community. Annually, Journal Citation Reports calculates and publishes impact factors for all the journals that are indexed by the Science Citation Index. The 1993 impact factors have been calculated by dividing 1993 citations to the 1991 and 1992 published items of a particular journal by the total number of published items in that journal from 1991 and 1992.
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An increasing number of patients with antibiotic-resistant propionibacteria have been described. Extensive sunbathing, even after sunscreen application, may facilitate development of skin cancers by suppressing natural immunity to these atypical growths.
BACKGROUND: Lentigines are common sun-induced benign melanocytic proliferations. Many therapies have been advocated, but few have been systemically evaluated. OBJECTIVE: We studied the effectiveness of two laser modalities in comparison with liquid nitrogen cryotherapy for lentigines. METHODS: We conducted a randomized, controlled, prospective trial comparing liquid nitrogen cryotherapy, argon laser light delivered by a Dermascan shuttered delivery system, and low-fluence carbon dioxide laser irradiation in the treatment of solar lentigines at 99 sites in 13 patients. RESULTS: Cryotherapy was more likely to produce substantial lightening than either argon or CO2 laser treatment, which gave similar results (p < 0.05 for both comparisons). The odds of an excellent results were about 50% higher with cryosurgery than with CO2 or argon laser therapy. CONCLUSION: Liquid nitrogen cryotherapy was superior to argon and CO2 laser therapy in the treatment of benign epidermal pigmented lesions. This study demonstrates that comparative rather than uncontrolled studies are needed to judge the relative efficacy of therapies for benign pigmented lesions such as lentigines.
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BACKGROUND AND DESIGN: Analysis of the most frequently cited dermatology articles and the journals in which they appear identifies and emphasizes the impact of works of colleagues and predecessors, recognizes key advances in cutaneous medicine and surgery, and adds useful data about historical developments in dermatology. Use of citation analysis to examine the dermatologic literature reveals quantitative information about authors, articles, and journals helpful in identifying classic works and high-impact journals. We analyze the characteristics of all dermatology articles cited 100 or more times in one of the 10 most highly ranked clinical dermatology journals as indicated by the Institute of Scientific Information (Philadelphia, Pa) database from 1945 through 1990 and also discuss the standard and, as well, more recently described bibliometric indexes for dermatologic journals. RESULTS: Thirty-one institutions located in 11 different countries produced 129 landmark articles. Ninety-two percent of the citation classics originated in the United States, United Kingdom, Sweden, and Germany. There were 16 authors with three or more top-cited articles. Fifty-two percent of the articles were of the clinical type, 22% were clinical review articles, and 26% discussed basic science topics. The mean number of authors has increased gradually over the past 80 years. The average classic article was published in 1969, peaked in popularity 9 years later with 26 peer citations, and received only 11 citations in 1990. CONCLUSIONS: Citation frequency and citation analysis reveal useful and interesting information about scientific communication. The data on citation classics we describe can be interpreted in many ways, but certainly reflects the attention that articles have received over the past 48 years. The half-life of the average citation classic of about 10 years reflects the rapid pace of advances in the science and practice of dermatology over the past several decades. This information, along with current bibliometric indexes, may assist physicians in optimizing the time they spend reading the medical literature.
BACKGROUND: The amount of biomedical information contained in scientific journals has grown to the point that complete coverage of this material is impossible. The number of articles and journals being published has been growing at an exponential rate since 1750. Thirty-four thousand references from 4000 journals are added each month to the National Library of Medicine MEDLINE database from among the more than 100,000 scientific journals now published. This increase in scientific literature reflects not greater productivity but simply a larger number of scientists at work. Most articles written are eventually published in the medical literature, but a large number of scientific articles are of less than optimal quality, and most scientific articles that are published are never cited. Articles of higher quality and usefulness cluster in a few journals that enjoy great use in medical libraries and high scores on bibliometric scores such as the Science Citation Index. OBSERVATIONS: To assess the reading habits of dermatologic trainees and evaluate how they cope with this information excess, a survey was distributed to 36 residents in three training programs. The average number of medical journal reading hours per month was 17; the number of hours devoted to reading issues of the Archives of Dermatology, the Journal of the American Academy of Dermatology, and the Journal of Investigative Dermatology were 3.2, 5.0, and 1.4, respectively; and the average resident read seven peer-reviewed journals, two to four dermatologic tabloids, and four peer-reviewed medical journals. CONCLUSIONS: Critically and consistently reading a limited number of high-quality peer-reviewed journals as well as taking advantage of information available through computer networks and bibliographic and full-text databases is the best approach to coping with the volume of medical literature. Translating this information into a change in attitude and modification of physician behavior is best accomplished when local role models incorporate new ideas into their practice and teaching. Modifications that would, in fact, bring about truly useful changes, such as decreasing the number of new publications, melding journals already present into smaller numbers of publications rather than instituting new journals, altering the "publish-or-perish" rules, and writing more comprehensive articles rather than multiple small contributions, all await fundamental alterations in long-accepted policies in medicine.
We tested the ability of the neuroleptic agent spiperone (8-[3-(p-fluorobenzoyl)propyl]-1-phenyl-1,3,8-triazaspiro-[4.5] decan-4- one) to influence the tissue swelling and leukocyte infiltration associated with T-cell--dependent immune responses, i.e., contact hypersensitivity reactions, in mice. Contact hypersensitivity reactions were elicited by applying the haptens oxazolone or dinitrofluorobenzene topically to one or both ears 5-8 d after epicutaneous sensitization. When spiperone was given subcutaneously at a dose of 30 or 150 mg/kg, 1 h after challenge with oxazolone, cutaneous contact hypersensitivity to this hapten was significantly diminished. When applied topically in concentrations as low as 0.08% (w/w), preparations of spiperone significantly suppressed both the tissue swelling and the leukocyte infiltration associated with the elicitation phase of contact hypersensitivity. Topical treatment with spiperone also suppressed the sensitization phase of contact sensitivity. However, mice treated topically with spiperone, unlike those treated systemically, exhibited no drowsiness or other evidence of central nervous system effects. Spiperone expresses both serotonin and dopamine receptor antagonist activity. However, unlike spiperone, the chemically unrelated serotonin antagonists, trazadone and mianserin, and the dopamine receptor antagonist, haloperidol, were not effective in suppressing contact hypersensitivity. Our results indicate that spiperone can have immunosuppressive effects on contact hypersensitivity reactions in the mouse, even when applied topically in doses that lack neuroleptic effects, and that the mechanism of action of spiperone on the immune response may be independent of its serotonin or dopamine receptor blocking properties.
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