Biomedical subjects
K A Arndt
Publications and source records attributed to K A Arndt.
Laser treatment of tattoos: a prospective, paired, comparison study of the Q-switched Nd:YAG (1064 nm), frequency-doubled Q-switched Nd:YAG (532 nm), and Q-switched ruby lasers.
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Basic laser principles.
Skin diseases have been treated with lasers since the early 1960s. The three principal chromophores in the skin--hemoglobin, melanin, and water--have different absorption spectra that selectively absorb certain wavelengths of electromagnetic radiation. A given wavelength and pulse duration will selectively treat a target containing a chromophore. The wide variety of lasers and their applications are discussed.
The homelands of top-cited articles.
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Are all 585 nm pulsed dye lasers equivalent? A prospective, comparative, photometric, and histologic study.
BACKGROUND: Flashlamp-pumped pulsed dye lasers (585 nm) are used to treat port-wine stains and other cutaneous vascular lesions. Strikingly different tissue effects were seen after two apparently similar 585 nm pulsed dye lasers at equivalent fluences were used. OBJECTIVE: We compared the photometric and histologic effects of two apparently similar 585 nm flashlamp-pumped pulsed dye laser systems. METHODS: The burn pattern and beam profile analysis of two Candela SPTL-1 lasers and two Cynosure Photogenica V lasers were compared. Various fluences and spot sizes of the Cynosure laser were placed on normal skin and evaluated for histologic change. RESULTS: Variation between the stated area of the spot and the actual measured area of the spot was found in all lasers studied. The area of the 5 mm spot of the two Candela lasers studied was 35% and 31% larger, respectively, than the stated area. The Cynosure lasers had areas that were 8% and 4% smaller than the stated area. Neither beam profile was uniform. The Candela laser maintained a gaussian-like distribution of energy, whereas the Cynosure laser beam profile resembled a top hat with a more even distribution of energy. Histologic studies confirmed the maintenance of vascular specificity without nonspecific thermal damage. CONCLUSION: When changing from one 585 nm pulsed dye laser to another and using supposedly equivalent fluences, one cannot guarantee that clinical results will be equivalent. In an effort to achieve consistent treatments when moving between lasers manufactured by different companies, it would be prudent to place a single spot of energy onto burn paper and measure the diameter of the spot.
Organizational impact in the dermatologic literature.
We revisit our citation data derived from 58,201 articles published between 1981 and 1994 in the 17 top-ranked peer-reviewed international dermatology journals to identify the institutions that house the people who have made the greatest impact on the dermatologic literature during this period. Using these citation data, we estimate an institution's impact in 2 ways. First, institutions are ranked by the gross number of citations to articles from 1981 to 1994 accurred during this same period. To recognize institutions whose articles, on average, have received higher numbers of citations, we also rank institutions by the average number of citations received by each article published by a particular institution (blended impact factor).
Dermatology.
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.
Dye laser treatment of port-wine stains: comparison of the continuous-wave dye laser with a robotized scanning device and the pulsed dye laser.
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.
The impact of dermatology journals.
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.
Peering at the dermatology literature.
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Dermatology.
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.
Laser therapy versus cryotherapy of lentigines: a comparative trial.
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.
My journal is smaller than your journal.
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Angiofibroma in tuberous sclerosis--argon laser.
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Use of short-course class 1 topical glucocorticoid under occlusion for the rapid control of erythrodermic psoriasis.
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