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Biomedical subjects

R Geronemus

Publications and source records attributed to R Geronemus.

At least 19 recordsLinked to original sources
PubMed2001

Tattoo darkening and nonresponse after laser treatment: a possible role for titanium dioxide.

OBJECTIVE: To examine relationships between chemical composition, biopsy findings, and clinical outcome in laser-treated tattoos. DESIGN: Observational nonblinded retrospective study. SETTINGS: University-based dermatology clinic and private practice. PARTICIPANTS: Twenty patients who underwent biopsy of laser-treated tattoos. MAIN OUTCOME MEASURES: Biopsy specimens were analyzed after laser treatment, and the depths of changed particles were recorded. Ultrastructure of the changed particles was examined by electron microscopy. Presence of inorganic chemicals was determined by x-ray diffraction. Correlation between x-ray diffraction, microscopy, and clinical response was attempted. RESULTS: Of the 20 tattoos, 7 lightened, 9 failed to change, and 4 darkened after laser treatment. There was a significant association between presence of titanium dioxide and poor response to laser therapy. Microscopic studies showed variable changes in the ink particles, but there was a trend toward residual deep green pigment in the resistant tattoos. Also, round dark stippling was observed superficially in the darkened specimens. CONCLUSIONS: Titanium is overrepresented in tattoos that respond poorly to laser treatment. Further studies are necessary to show whether this metal is the primary cause of this poor response.

Coloring Agents↗
PubMed2001

Hemangiomas: evaluation and treatment.

BACKGROUND: Hemangiomas are common skin tumors of infancy that have undergone recent changes in nomenclature, methods of evaluation, and treatment. OBJECTIVE: To review the nomenclature, epidemiology, evaluation, and treatment of common hemangiomas. METHODS: A literature search was conducted utilizing MEDLINE and the Cochrane library databases. Text search words used were "hemangioma" and "infancy." The clinical experience of the authors was also used to formulate the review. RESULTS: There have been many advances in nomenclature and therapeutic options for children with hemangiomas. Hemangiomas are proliferative tumors of infancy that should be distinguished from structural malformations, such as port-wine stains and lymphangiomas. CONCLUSION: Natural involution remains a viable treatment option for the majority of patients with uncomplicated hemangiomas. Excisional surgery, laser, and pharmacologic remedies are indicated for a subset of complicated hemangioma patients.

Hemangioma↗
PubMed1998

Treatment of spider veins with the 595 nm pulsed-dye laser.

BACKGROUND: Previous attempts to treat spider veins with the conventional 585 nm pulsed-dye laser with a 0.5-ms pulse duration have been relatively ineffective. Recently, a new pulsed-dye laser that is tunable from 585 to 600 nm with a pulse duration 3 times longer than previously available lasers has preliminarily been shown to be effective for treatment of spider veins. OBJECTIVE: Our purpose was to evaluate the effectiveness of multiple treatments with the tunable long-pulse dye laser in treatment of spider veins of the lower extremity. METHODS: Ten female volunteers were treated in two separate areas containing blue or red linear spider veins less than 1.5 mm in diameter. Treatments were administered with the pulsed-dye laser with a 1.5-ms pulse duration and 595-nm light at fluences of 15 and 20 J/cm2, and each subject received a total of 3 treatments at each site, administered at 6-week intervals. Photographs were taken before and 6 weeks after the last treatment. RESULTS: Computer-based image analysis showed clearing of more than three fourths of veins after 3 treatments with 15 or 20 J/cm2. Side effects were minimal and the treatments were well tolerated. CONCLUSION: The 595 nm, 1.5 ms pulse duration, pulsed-dye laser is safe and effective for treating blue or red spider veins of the lower extremities less than 1.5 mm in diameter in nontanned patients with Fitzpatrick skin types I and II. Multiple treatments improve on the results obtained after a single treatment.

Adult↗
PubMed1995

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↗
PubMed1993

Cosmetic tattoo ink darkening. A complication of Q-switched and pulsed-laser treatment.

BACKGROUND: High-energy, short-pulse lasers, eg, Q-switched lasers, emitting visible and near-infrared light have recently been developed for removing tattoos, with little risk of scarring. The mechanisms of action, and possible adverse effects other than scarring and hypopigmentation, are not fully understood. OBSERVATIONS: We describe five cases of pulsed-laser-induced, immediate, irreversible darkening of cosmetic, white, flesh (skin-color), and pink-red colored tattoos. Irreversible ink darkening can be an insidious complication, because immediate whitening of the skin temporarily obscures the subsequently impressive color change. Among these cases, irreversible ink darkening occurred with Q-switched ruby (694 nm), Q-switched neodymium (Nd):YAG (1064 nm/532 nm), and pulsed green dye (510 nm) lasers. Attempts to remove the darkened ink with further laser treatment failed in two cases, and surgical excision was necessary. In the other three cases, subsequent laser treatments successfully removed the darkened ink. The red cosmetic tattoo ink used in one of the cases was placed in agar in vitro and was converted to a black compound immediately on Q-switched ruby laser exposure. Ferric oxide, a brown-red ingredient commonly used in cosmetic tattoos, was similarly tested and blackened in vitro by Q-switched ruby laser exposures. CONCLUSIONS: Although most tattoos are not darkened by laser treatment, short-pulsed lasers over a wide spectrum can cause immediate darkening of some tattoo inks. Patients should be warned of the potential for irreversible cosmetic tattoo darkening, and test-site exposures should be performed prior to treatment. In some cases, subsequent laser treatments may remove the blackened ink. The mechanism probably involves, at least for some tattoos, reduction of ferric oxide (Fe2O3, "rust") to ferrous oxide (FeO, jet black), but the chemical reaction that is involved remains unknown.

Adult↗
PubMed1991

Invasive squamous cell carcinoma in a patient with epidermodysplasia verruciformis.

A patient with epidermodysplasia verruciformis died of intracranial invasion by squamous cell carcinoma (SCC). A biopsy of clinically normal skin had revealed perineural invasion by malignant keratinocytes. Because SCCs arising in patients with epidermodysplasia verruciformis may be biologically aggressive, it is best to excise them with careful control of the surgical tissue margins.

Abducens Nerve↗
PubMed1991

Lasers in the treatment of skin cancer.

The development and use of various laser systems for the treatment of carcinomas of the skin constitute a relatively new therapeutic approach. Because the skin is a readily accessible organ, it is an excellent site at which to attempt different therapeutic modalities. What is truly astounding has been the development of specific lasers designed to treat certain dermatologic problems. Because the field of laser biotechnology is still rapidly emerging, it is very likely that new lasers and modifications of existing ones will improve our ability to treat skin cancer and precancerous conditions.

Dermatologic Surgical Procedures↗
PubMed1990

Treatment of port-wine stains during childhood with the flashlamp-pumped pulsed dye laser.

Seventy-three patients between the ages of 3 months to 14 years (average age 6 years 2 months) with port-wine stains were treated with the flashlamp-pumped pulsed dye laser. More than 75% lightening was achieved with an average of 2.5 treatments in 33 patients (45%), 50% to 74% lightening after an average of 1.7 treatments in 31 (42%), 26% to 49% lightening after 2 treatments in 5 (7%), and less than 25% lightening after 1 treatment in 4 (5%). The overall average lightening after one treatment was 53%. The percentage of lightening increased as the number of treatments increased. Three patients had 100% clearance of the port-wine stain. Patients aged between 3 months and 6 years (44 patients) had a better response after the first treatment (55% lightening) than did patients aged between 7 and 14 years (29 patients with a 48% lightening; p = 0.027). Complications included cutaneous depressions in four patients, hyperpigmentation in 16 patients, and hypopigmentation in three patients. All complications were transient and disappeared completely.

Adolescent↗
PubMed1990

Presuturing in alopecia reductions.

The technique of presuturing for alopecia reductions is described. With this procedure, the area of potential reduction is sutured 12-24 hours prior to surgery to enhance the laxity of the scalp.

Alopecia↗
PubMed1989

The association of lichen planus of the penis with squamous cell carcinoma in situ and with verrucous squamous carcinoma.

Two cases of squamous cell carcinoma (SCC) of the penis, one verrucous type and one in situ, arising in association with an inflammatory dermatosis most consistent with lichen planus, are described. Although SCC has previously been reported to have arisen from lichen planus of the oral mucosa, these are the first reported cases of the coexistence of these processes on the penis.

Adult↗
PubMed1986

DERM/RX. A computer aid to the management of diseases of the skin.

DERM/RX (dermatologic therapy) is a computerized data base representing a compendium of therapeutic management options for over 600 diseases of the skin. This data base is housed in the National Headquarters of the American Academy of Dermatology in Evanston, Illinois. It is accessible via DERM/INFONET to members of the American Academy of Dermatology via telephonic communication lines that blanket the United States. The data base is constantly updated by the Task Force on DERM/RX of the Committee on Biomedical Communications of the American Academy of Dermatology.

Humans↗
PubMed1982

Studies of carbohydrate metabolism after hemodialysis and hemofiltration in uremic patients.

To assess the effects of dialysis or hemofiltration on carbohydrate metabolism in uremia, we performed intravenous (IV) glucose tolerance tests (IV GTTs) after an overnight fast 48 hours following the last treatment in ten patients with chronic renal failure. Samples were obtained for plasma glucose, insulin, glucagon, and growth hormone levels throughout the GTTs in addition to basal samples for levels of plasma potassium and bicarbonate. The IV GTTs were performed at the end of a four-month period of standard hemodialysis (period 1) and then at the end of a four-month period of hemofiltration (period 2). Patients had mild glucose intolerance that did not change after hemofiltration, although the exaggerated insulin responses to glucose administration did significantly decrease in period 2. The fasting hyperglucagonemia did not decrease after hemofiltration but exhibited normal suppression with IV glucose. Levels of basal plasma bicarbonate and basal plasma potassium did not change significantly in period 2. Further studies investigating the beneficial metabolic effect of hemofiltration would seem to be indicated based on the data reported herein.

Adult↗