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Biomedical subjects

N J Lowe

Publications and source records attributed to N J Lowe.

At least 19 recordsLinked to original sources
PubMed1995

Low doses of repetitive ultraviolet A induce morphologic changes in human skin.

Repetitive exposure of skin to sunlight is known to result in dermatoheliosis, characterized by photoaging and carcinogenesis. It has been demonstrated previously that relatively large amounts of ultraviolet (UV) A can produce photodamage and it is believed that UVB plays a major role in the induction of photodamage and photocarcinogenesis. The study reported here determines the cutaneous effects of minimal erythemal amounts of solar-simulated UV radiation as well as suberythemal and minimal erythemal doses of UVA. Previously non-sunexposed human skin was irradiated twice weekly for 24 weeks. Biopsies were obtained 12, 24 and 36 weeks after the initial irradiation and assessed for both epidermal and dermal alterations. Dermal elastic tissue content was measured via computerized image analysis. All UV treatment regimens produced observable epidermal and dermal changes. These alterations were observed after only 12 weeks of twice-weekly irradiation and were still evident 12 weeks after the final irradiation. Interestingly, UVA irradiation produced a decrease in elastic tissue content whereas solar-simulated UV produced a slight increase. Most notable were the changes produced by the suberythemal dose of UVA. Surprisingly, this relatively low UVA dose produced a reduction in elastic tissue content. The results of this investigation demonstrate that small amounts of UVA or solar-simulated UV are capable of producing cutaneous photodamage. These findings suggest that even suberythemal doses of repetitive UVA may lead to photoaging of the skin and that there is a need for daily broad spectrum UV protection.

Adult↗
PubMed1995

Skin resurfacing with the Ultrapulse carbon dioxide laser. Observations on 100 patients.

BACKGROUND: The Ultrapulse carbon dioxide (CO2) laser has been shown to be a highly effective treatment for photodamaged skin including improvement of rhytides, precancerous and benign skin lesions, as well as superficial benign pigmented lesions. OBJECTIVE: We describe our experiences using the Ultapulse CO2 laser in treating 100 patients with different severities of photodamaged skin. METHODS: All patients had moderately or severely photodamaged skin and were selected for treatment with the Ultrapulse CO2 laser to evaluate the efficacy and toxicity of this treatment. The patients were placed on a pretreatment regimen for 2-6 weeks prior to receiving treatment with the Ultrapulse CO2 laser. Patients were evaluated for pre- and posttreatment severity of photodamage. In addition, skin surface replicas were obtained in selected patients and evaluated by computer image analysis technology. RESULTS: At 1 month post-laser treatment, 68 patients received a moderate improvement, five patients achieved a marked improvement, and the remaining 27 patients showed minimal improvement. By 2 months post-laser treatment, 20 of the 27 patients who at 1 month showed only minimal improvement revealed a moderate to marked improvement from baseline. All the patients studied developed a transient erythema that lasted up to 6 weeks, and many of these patients showed a transient hyperpigmentation that persisted for up to 4 months. CONCLUSION: The Ultrapulse CO2 laser is confirmed as an effective treatment for skin resurfacing of photodamaged skin.

Adult↗
PubMed1995

Laser resurfacing in pigmented skin.

BACKGROUND: Laser skin resurfacing is a very promising new treatment for solar elastosis and acne scars. The Ultrapulse carbon dioxide (CO2) laser and the SilkTouch flashscanner allow precise depth control and char-free ablation. Earlier studies have been done mainly on Caucasian skin types I and II, but very little data were available on pigmented skin. OBJECTIVE: The purpose of this study is to assess the efficacy and safety of laser skin resurfacing in skin types III and IV. METHODS: Thirty Asian and Hispanic patients were treated for facial rhytides and acne scars. All patients were instructed to use tretinoin cream 0.05%, hydroquinone 5%, and desonide 0.1% cream nightly for 2-4 weeks prior to the laser treatment. The Ultrapulse 5000C CO2 laser with the Truespot 3-mm collimated handpiece at the setting of 250-450 mJ per pulse, or the Silk-Touch flashscanner at the setting of 5-7 W, 0.2-second pulse duration, and 4-mm (M) spot size, was used. Patients were evaluated clinically, and global response was assessed by both clinicians and patients. RESULTS: The facial rhytides and acne scars improved 25-50% in all patients after one laser treatment. The most common side effects were persistent erythema that resolved on the average of 6 weeks. Hyperpigmentation occurred, but was reduced with regular use of tretinoin, hydroquinone, and desonide cream both pre- and postoperatively along with use of broad spectrum sunscreen after treatments. CONCLUSION: Laser skin resurfacing can be used to treat facial rhytides and acne scars in skin phototypes III and IV. When proper pre- and postoperative management is implemented, the risk of dyspigmentation can be reduced.

Acne Vulgaris↗
PubMed1995

Laser skin resurfacing. Pre- and posttreatment guidelines.

BACKGROUND: Carbon dioxide laser skin resurfacing using either ultrapulsed lasers or scanning skin lasers has evolved as an effective method of treating photodamaged skin. OBJECTIVE: The purpose of this paper is to describe appropriate pre- and posttreatment regimens to ensure the optimum response to laser therapy. METHODS: We describe our experiences with 30 patients treated with laser skin resurfacing using different pre- and posttreatment regimens. Patients were evaluated by physicians as regards to their responses to and recovery from laser therapy. Some patients agreed to skin biopsy and cutaneous patch testing of topically applied agents. RESULTS: Eighty percent of patients achieved good to excellent improvement. Sixty-five percent of patients undergoing laser skin resurfacing developed contact dermatitis to several topical agents. Patch testing was negative on normal skin for contact allergy, suggesting a primary irritant reaction in laser-treated skin. Post-laser hyperpigmentation and erythema were the most noted immediate and mid-term side effects to laser resurfacing. An optimum pretreatment regime includes topical retinoids, skin lightening agents, and, immediately pretreatment, oral anti-herpes simplex medication plus oral antibiotics. An optimum posttreatment regimen includes minimizing topical therapy with the use of dilute acetic acid facial soaks. In addition, oral anti-herpes simplex medications and broad spectrum antibiotics are continued for 7 days post-laser resurfacing. CONCLUSION: Laser skin resurfacing is an evolving means of treating photodamaged skin. Carefully selected pre- and posttreatment regimens, ideally under dermatologic supervision, are required to obtain optimum results.

Dermatologic Surgical Procedures↗
PubMed1995

Infraorbital pigmented skin. Preliminary observations of laser therapy.

BACKGROUND: The presence of infraobital dark skin, often known as dark circles under the eyes, is a frequent cosmetic concern. There has been little reported on therapy of this condition. One group of patients was determined to have dermal melanin deposition, which we treated with a Q-switched ruby laser. OBJECTIVE: Our study evaluated the clinical and histological appearance of infraobital skin pigment in 17 patients with dermal melanin deposition treated with a Q-switched ruby laser. METHODS: Seventeen patients with melanin deposition were treated with the Q-switched ruby laser (694 nm) with a pulse width of 28 nanoseconds and fluences of 7.5 J/cm2. Response to treatment was assessed by an independent investigator with patient and photograph evaluation. Skin Biopsies were obtained in nine of the 17 patients. RESULTS: Of those patients treated with one Q-switched ruby session, 23.5% achieved a greater than 50% response. Of those treated twice, 88.9% achieved greater than 50% response. In postreatment skin biopsies there was reduction of dermal melanin deposition. CONCLUSIONS: Patients with infraobital pigmented skin due to dermal melanin deposition may be considered candidates for Q-switched Ruby laser treatment.

Adult↗
PubMed1994

Photoreactions with a fluoroquinolone antimicrobial: evening versus morning dosing.

Quinolone antimicrobials absorb ultraviolet radiation and, with appropriate drug concentrations, may cause photoreactions. Photoreactions have been reported for several quinolones, including lomefloxacin, a difluorinated quinolone antimicrobial. This study was designed to determine whether the interval between administration of lomefloxacin and exposure to ultraviolet A (UVA) light would affect skin responses. The minimal erythema dose (MED) and severity of local reactions were the main parameters of evaluation. Exposure to UVA radiation 2 hours after morning dosing caused an increase in skin sensitivity as assessed by changes in MED (p < 0.05). No changes were observed with exposure 16 hours after evening dosing (p = 1.00). Edema and blisters at the radiation sites were observed in only the morning dosing group. A significant negative correlation was observed between lomefloxacin plasma concentrations and change MEDs (r = -0.72; p < 0.05). An evening dosing strategy may minimize the risk of phototoxic effects.

Adult↗
PubMed1994

Q-switched ruby laser. Further observations on treatment of professional tattoos.

The Q-switched ruby laser is effective in the treatment of amateur tattoos and other pigmented lesions. Previous studies have shown that, though amateur tattoos usually respond well, professional tattoos show greater resistance to clearing. Our study evaluates the treatment of 20 patients with 28 professional (blue, green, black) tattoos by a Q-switched ruby laser with a 28-ns pulse width, and using high energy fluences up to 10 J/cm2. Responses proved to be good to excellent among these patients, who needed fewer treatments than previously reported.

Adolescent↗
PubMed1994

Flashlamp-pumped pulsed dye laser treatment of port-wine stains.

BACKGROUND: Port-wine stains, or capillary malformations, occur in 0.3-0.5% of newborns and have been shown to be very responsive to treatment with a pulsed dye laser (585 nm, 450 microseconds). Lesional characteristics that may help predict the ease of response to therapy have not been delineated. There exists a great range of variation in response to treatment. OBJECTIVE: A retrospective study of 133 patients with 140 port-wine stain malformations being treated with the flashlamp-pumped pulsed dye laser was undertaken. Lesion characteristics such as color and location, patient age, and skin type were evaluated as to their correlation with clinical response. Adverse sequelae were evaluated as well. METHODS: Charts of treated patients were reviewed and results tabulated. The five treating physicians were each responsible for reviewing and evaluating their own patients. Patients were treated at 8-12-week intervals using slightly overlapping pulses with fluences from 5.5 to 7.5 J/cm.2 RESULTS: Factors favoring a positive clinical response were pink lesion color, lesion location of the head and neck, patient age less than 10 years, and patient skin types I-III. Factors having a more negative impact on clinical result include purple lesion color, lesion location on the distal extremities, patient age > 50 years, and skin types IV and V. CONCLUSION: Examination of various patient and lesional characteristics shows trends that may be useful in a predictive manner regarding ease of treatment with the flashlamp-pumped pulsed dye laser.

Adolescent↗
PubMed1993

Nevus of Ota: treatment with high energy fluences of the Q-switched ruby laser.

BACKGROUND: The nevus of Ota is a benign dermal melanocytic lesion that has previously proved difficult to treat. Recently, the Q-switched ruby laser has been reported to be successful in treating benign pigmented lesions and tattoos. OBJECTIVE: Our study evaluates the treatment of 16 patients with nevus of Ota with the Q-switched ruby laser (694 nm). METHODS: Sixteen patients with nevus of Ota were treated with the Q-switched ruby laser with a pulse width of 28 nsec and energy fluences ranging from 7.5 to 10 J/cm2. Response to treatment was assessed by an independent investigator with photographs. RESULTS: The average number of treatments was 3.8 per patient. After two treatments, 44% of patients showed a 50% or greater improvement. After three treatments, 85% of patients showed a 50% or greater improvement; after four treatments, 100% of patients showed 50% or greater improvement. No patients had permanent textural changes or scarring. CONCLUSION: High-energy fluences of the Q-switched ruby laser lead to significant improvement without scarring of nevus of Ota after a few treatments.

Adolescent↗
PubMed1993

Flash lamp-pumped dye laser treatment of telangiectasia.

BACKGROUND: Although many treatment modalities are effective in the treatment of essential telangiectasia, most have a risk of scarring and or incomplete obliteration of the dilated vessels. The Candela flash lamp-pumped dye laser has been regarded as highly selective for blood vessel ablation with virtually no risk of scarring. OBJECTIVE: To present a study of 182 patients who underwent this treatment. RESULTS: Good to excellent response was seen in 97.5% of these patients. No scars were seen in any of the patients studied. Patients described the degree of discomfort as mild to moderate and found the post-treatment purpura an acceptable phase of healing, if advised preoperatively. CONCLUSION: We found the laser to be safe and effective in the treatment of facial telangiectasia.

Adolescent↗
PubMed1992

Home ultraviolet phototherapy.

Home UV phototherapy is extremely popular with many psoriasis patients. However, it is essential that they understand the need for regular skin examination by the dermatologist. Patients with psoriasis are not trained nor are many nondermatologist physicians to recognize the early features of many skin cancers, and continued home UV therapy in the presence of such skin cancers is clearly unwise for the safety of that patient. The use of UVA tanning salon treatments in the therapy of psoriasis is usually unsuccessful and is extremely unwise with concomitant psoralen and drug therapy. This is to be discouraged, and the patient should always be treated with PUVA in the dermatologist's office with carefully monitored UVA machines and staff trained in the administration of PUVA phototherapy.

Humans↗
PubMed1991

Acitretin plus UVB therapy for psoriasis. Comparisons with placebo plus UVB and acitretin alone.

UVB radiation is beneficial for the treatment of psoriasis vulgaris. Patients with recalcitrant disease, however, are slow to respond to UVB phototherapy with and without the use of coal tars or emollients. Etretinate and, more recently, acitretin have proved useful, but clinical improvement is slow when they are used as monotherapy in plaque psoriasis. Each drug also produces side effects, some of which are dose related. This study was designed to compare results of treatment with UVB combined with either acitretin (50 mg/day) or placebo to determine if psoriasis would respond faster and to less cumulative exposure to UVB and acitretin. The psoriatic disease cleared to a greater degree in patients treated with acitretin-UVB with fewer treatments and smaller amounts of UVB radiation than in patients treated with either placebo-UVB or acitretin alone.

Acitretin↗
PubMed1991

UVABA therapy for psoriasis. Efficacy with shortened treatment times with the combined use of coal tar, anthralin, and metal halide ultraviolet machines.

Rapid clearing of psoriasis in a psoriasis treatment center setting has been obtained with a combination of short-contact coal tar, phototherapy from high-pressure metal halide lamps (consisting of UVA and UVB), and short-contact high-potency anthralin therapy. These intensive 1 1/2- to 2-hour treatment sessions done three or four times weekly were as efficacious as reported responses to PUVA therapy or conventional psoriasis day care therapy. The treatment schedule allows minimal time away from work, decreased hours per week in contact with crude coal tar, shortened UV treatment times, decreased cost, and a low risk of side effects. It is suggested that the use of UVA and UVB combined with anthralin (UVABA) is effective for many patients with moderate to severe psoriasis.

Adolescent↗