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Biomedical subjects

J S Dover

Publications and source records attributed to J S Dover.

At least 55 records · Page 3Linked to original sources

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.

Blood Vessels↗

Laser skin resurfacing.

There has always been interest in looking younger, but recently there seems to have been an explosion of public interest in facial rejuvenation. Physicians have been treating photodamaged skin for many years by removing the epidermis and a variable thickness of dermis with dermabrasion or chemical peels, with the expectation that reepithialization and collagen remodeling will result in a more youthful appearance. With the recent development of short-pulsed high-peak power and rapidly scanned carbon dioxide (CO2) lasers, the ability to remove photodamaged skin in a precise and reproducible manner while leaving behind a narrow zone of thermal damage has been achieved. This development has generated tremendous interest in laser skin resurfacing as a technique to reverse photoaging.

Face↗

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.

Dermatologic Agents↗

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.

Adolescent↗

Lasers.

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Humans↗

Immunohistological comparison of granulated cell proteins in induced immediate urticarial dermographism and delayed pressure urticaria lesions.

Urticarial dermographism and delayed pressure urticaria are two forms of physical urticaria which are well defined clinically and histologically. Previous studies have shown eosinophil granule protein deposition in urticarial reactions, including chronic urticaria, solar urticaria and delayed pressure urticaria. To evaluate and compare the involvement of granulated inflammatory cells in urticarial dermographism and delayed pressure urticaria, we studied sequential biopsies of induced lesions of urticarial dermographism and delayed pressure urticaria by indirect immunofluorescence, to detect eosinophil granule major basic protein (MBP) and neutrophil granule elastase. Biopsies from dermographic lesions at time 0, 5 min, 15 min, 2 h and 24 h, showed few infiltrating eosinophils, with minimal extracellular MBP deposition, and a few infiltrating neutrophils, with minimal neutrophil elastase deposition, throughout the evolution of the lesions. Sequential biopsies of delayed pressure urticaria at time 0, 20 min, 6, 12 and 24 h, showed eosinophil infiltration with extensive MBP deposition beginning at 20 min, and neutrophil infiltration with variable elastase deposition beginning at 20 min. Control tissue specimens from normal volunteers showed neutrophil infiltration and slight degranulation, but no eosinophil infiltration or degranulation. Comparison of urticarial dermographism with delayed pressure urticaria showed marked differences in the patterns of infiltration. Delayed pressure urticaria, with eosinophil and neutrophil degranulation, was strikingly similar to the IgE-mediated late phase reaction. In contrast, eosinophil and neutrophil involvement in urticarial dermographism was minimal. Considering the extent of eosinophil granule protein deposition and the biological activities of the eosinophil granule proteins, the findings in delayed pressure urticaria point to an important pathophysiological role of eosinophils in the disease.

Blood Proteins↗

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.

Dermatology↗

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.

Argon↗

Dermatology.

Explore the source record for details and available documents.

Dermatology↗