Multidrug-resistant tuberculosis.
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Cross Infection↗
Biomedical subjects
F Urbach
Publications and source records attributed to F Urbach.
Evaluation of halobetasol propionate ointment in the treatment of plaque psoriasis: report on two double-blind, vehicle-controlled studies.
The results of two studies are presented that reveal the efficacy and safety of 0.05% halobetasol ointment in the treatment of patients with plaque psoriasis of at least moderate severity. Both multicenter studies were randomized, double-blind, and vehicle controlled, and study medications were applied twice daily for 2 weeks. One study was a paired-comparison (PC); the other study was of parallel-group (PG) design. Both studies called for evaluations at entry (week 0) and after 1 and 2 weeks of treatment. The PC study enrolled 100 patients; the PG study enrolled 110 patients; 204 patients provided efficacy data over both studies. In the PC study, plaque elevation, erythema, and scaling, at least moderately severe at entry, showed at the end of treatment both statistical (p less than or equal to 0.0003) and clinical significance (all greater than 1-unit difference on the rating scale) favoring 0.05% halobetasol ointment over vehicle. Pruritus (initially mild) and total score also showed statistically significant treatment differences favoring halobetasol at the final evaluation. Patient global responses for "effectiveness" and "overall rating" favored 0.05% halobetasol ointment over vehicle. In the PG study, induration, erythema, and scaling, at least moderately severe at entry, showed at the end of treatment both statistically and clinically significant differences favoring 0.05% halobetasol ointment over vehicle. Physician's global evaluation favored 0.05% halobetasol ointment over vehicle after 2 weeks of use. No patients were released from either study because of adverse events. No systemic adverse events or findings of skin atrophy were reported in these studies. Reports of "stings" or "burns" were equally divided between halobetasol and its vehicle.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Potential health effects of climatic change: effects of increased ultraviolet radiation on man.
There is scientific evidence that stratospheric ozone concentration has declined over the Northern Hemisphere in the past 20 years, and projections based on various assumptions about future release of chlorofluorocarbon gases and other contaminants suggest that this decline will continue into the next century. The effects on human health secondary to increase in biologically effective ultraviolet radiation are expected to consist of increases in nonmelanoma skin cancer and malignant melanoma of the skin, possible alteration of immune response, and development of lens cataracts. The recent and projected increases in skin cancer and changes in human immune responses are discussed.
Adaptation, Physiological↗
Incidence of nonmelanoma skin cancer.
Nonmelanoma skin cancers are the most common malignant neoplasms of fair-skinned people, in many sunny countries exceeding the total of all other neoplasms. The evidence that the primary causal agent is chronic repeated exposure to solar ultraviolet radiation is overwhelming. The incidence of basal cell carcinoma is always greater than that of squamous cell carcinoma, varying by latitude from 10:1 to 2.5:1. The incidence of nonmelanoma skin cancer has been increasing by 2% to 3% per year, at least in the United States. Most likely, this is caused by greater outdoor exposure for leisure and social reasons.
Africa↗
Effects of chemicals on photobiologic reactions of skin.
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Animals↗
The biological effects of increased ultraviolet radiation: an update.
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Eye Injuries↗
Potential effects of altered solar ultraviolet radiation on human skin cancer.
There is highly significant evidence that non-melanoma skin cancers are primarily due to chronic repeated exposure to solar ultraviolet radiation, and that there is a significant, although somewhat different relationship between solar radiation and the development of cutaneous malignant melanoma. Recent experimental and epidemiologic studies show that the biologically most effective UVR wavelengths are in the segment of the solar UVR spectrum that would be significantly augmented by decreases in stratospheric ozone content. A recent report on measurements of column ozone changes in the stratosphere has shown that in the past 18 yrs, there has been an ozone decrease between 2 and 3%, greater in the winter months, and somewhat differing with latitude in the Northern Hemisphere. Calculations of the relationship of ozone decrease to increase in biologically effective UVR show great dependence on the biologic action spectrum assumed. Based on extensive epidemiologic studies of skin cancer incidence, it appears that the estimated increase in biologically effective UVR due to the measured ozone decreases in the past (almost) two decades are not likely to be the cause of the sharp increase in skin cancer incidence which have been observed. Most likely these increases in incidence are the result of increasing personal exposure, due to striking changes in personal behavior that have taken place for social reasons. However, there is every reason to believe that increases in biologically effective UVR due to stratospheric ozone decreases will have significant impact on human skin cancer incidence in the future.
Animals↗
Testing the efficacy of sunscreens: effect of choice of source and spectral power distribution of ultraviolet radiation, and choice of endpoint.
The problems inherent in testing the protective efficacy of sunscreens are reviewed. Of primary importance are: the spectral power distribution of the test light source, which should simulate the ultraviolet radiation of midlatitude, midsummer sunlight; definition of minimal erythema of skin, and equilibration of light source and filters prior to testing.
Administration, Topical↗
Narrow-band UV radiation and induction of dermal elastosis and skin cancer.
A narrow-band UV light source with emission peaks at 292, 300, 307, 317, and 336 nm was developed and used to irradiate whole cages of hairless mice. The purpose was to obtain experimental information on the action spectrum for photocarcinogenesis and dermal elastosis. Groups of 20 mice were irradiated with 500 J/m2 daily, 5 times per week during one year. The total dose was 130 kJ/m2. All mice irradiated with 292 nm and 300 nm developed squamous cell carcinomas. None in the other groups developed malignant skin tumors. Elastosis was estimated quantitatively. The elastic fibers covered 3% of a representative microscopic section of dermis in the control group. In the groups irradiated with peaks at 336 nm, 317 nm, 307 nm, 300 nm, and 292 nm the corresponding percentages were 6%, 13%, 28%, 32%, and 36%, respectively. The shorter the wavelengths the more pronounced was a subepidermal zone replacing the elastotic tissue to the deeper dermis. This zone stained corresponding to a content of glycosaminoglycans (GAG), sulphated GAG, hyaluronic acid, mature collagen, and new reticulin.
Animals↗
Biologically effective ultraviolet radiation: surface measurements in the United States, 1974 to 1985.
Recent reports of stratospheric ozone depletion have prompted concerns about the levels of solar ultraviolet radiation that reach the earth's surface. Since 1974 a network of ground-level monitoring stations in the United States has tracked measurements of biologically effective ultraviolet radiation (UVB, 290 to 330 nanometers). The fact that no increases of UVB have been detected at ground levels from 1974 to 1985 suggests that meteorological, climatic, and environmental factors in the troposphere may play a greater role in attenuating UVB radiation than was previously suspected.
Humans↗
Scope of clinical photodermatology.
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Dermatology↗
Comparative efficacy of two dosage forms of oral methoxsalen in psoralens plus ultraviolet A therapy of psoriasis.
Two alternate oral formulations of 8-methoxypsoralen, one liquid and the other crystalline, were evaluated in a double-blind trial for their comparative efficacy in combination with ultraviolet A (UVA) light in the treatment of severe psoriasis. With the liquid formulation a greater proportion of patients achieved a good clinical result within the 20 treatment sessions than patients receiving the crystalline formulation. This difference is even more striking using a more rigorous criterion of clearance. Among all patients who achieved clearance, no significant differences were seen in either the number of treatments required or in the total UVA energy employed between the two groups. The preceding clinical results are discussed in light of published pharmacokinetic data.
Administration, Oral↗
Effect of indoor lighting on normal skin.
A small but measurable component of some indoor lighting is ultraviolet radiation (UVR); whether it is sufficient to modify the indoor worker's risk for chronic skin changes is not directly answerable with available technology. A first approach to this question involves a) estimating a range of annual background solar exposure for indoor workers currently at risk; b) determining whether, and at what levels, UVR exposure is a part of specified indoor lighting; and c) calculating the increment in risk implied by a and b. This algorithm predicts that some lighting conditions that meet NIOSH recommended standards would still result in significant increases in the risk of cumulative UVR damage, including skin cancer. More information concerning actual exposure conditions, the relation of spectral effectiveness for luminosity and UVR production, and dose-time reciprocity are required to improve our predictions of long-term cutaneous effects of indoor lighting.
Erythema↗
Bowen's disease and squamous cell carcinoma. Occurrence in a patient with psoriasis after topical, systemic, and PUVA therapy.
Multiple lesions of Bowen's disease and squamous cell carcinoma on the penis and pubic areas developed in a 32-year-old patient with psoriasis who was undergoing treatment with psoralen and long-wave ultraviolet radiation (PUVA). A cumulative dose of more than 3,700 joules/sq cm of UVA had been administered over a three-year period. This case may be an early warning of possible carcinogenicity of PUVA therapy, alone or as part of sequential therapy with other agents.
Adult↗
Enhancement of experimental photocarcinogenesis by topical retinoic acid.
Topical application of retinoic acid (RA) solutions greatly enhanced the response of hairless mouse skin to a moderate dose of simulated sunlight. Tumors appeared much earlier, and in much greater numbers, in animals treated daily with 1 or 10 micrograms of RA in methanol immediately after 2 h exposure to a xenon arc filtered through 2 mm of Schott WG 320 glass (approximately equivalent in human erythema effectiveness to 5 min of mid-summer noon solar exposure in northern mid-latitudes), compared to mice treated with light and methanol only. The higher amount of RA, in combination with light, produced moderate epidermal hyperplasia and some scaling and transient erythema, but no gross ulceration or inflammation of skin. The lower amount of RA, though about equally effective in carcinogenesis, produced minimal epidermal hyperplasia compared to the ultraviolet radiation + methanol control.
Administration, Topical↗
Normal T-lymphocyte function in psoriatic patients undergoing methoxsalen photochemotherapy.
Peripheral blood lymphocytes from psoriatic patients undergoing photochemotherapy using oral 8-methoxypsoralen and high-intensity long-wave ultraviolet radiation, were isolated and their ability to respond to phytohemagglutinin and to form spontaneous rosettes with sheep red blood cells was measured in vitro. Seventeen patients were investigated who had received 200 to 3700 Joules/cm2 of ultraviolet radiation over a 6- to 33-month period. No significant defects in lymphocyte blastogenesis or E-rosette formation were detected in these patients.
Adult↗
Aging, environmental influences, and photocarcinogenesis.
Repeated exposure of human skin to solar ultraviolet radiation (UVR) over a period of many years is responsible for the induction of most nonmelanoma skin cancers in man. The tumors are progressively more common in chronologically older people. Is this fact purely a function of adequate dose accumulation and development time, or is tumor expression influenced by "physiological age"? The answer to this question influences risk estimates of the results of atmosphere modification. Data from animal studies indicate that the tumor incidence is affected by dose-delivery factors and not just by the accumulated lifetime dose. In addition, young mice are more prone to tumor induction by a given UVR dose than are older animals. Because the quanlity and quantity of the stimulus (UVR) can be readily manipulated and accurately described, studies on photocarcinogenesis offer distinct possibilities for untangling some of the interactive variables in the aging process.
Aged↗
Mycosis fungoides, nitrogen mustard and skin cancer.
The prevalence of epithelial cancer was determined in 202 patients with mycosis fungoides and the Sézary syndrome and was found to be 10.5%. In an attempt to establish a possible association with topically applied nitrogen mustard, it was noted that 4.0% of these patients had lesions prior to nitrogen mustard therapy (although over half subsequently developed further lesions) and 6.5% of the patients developed them de novo after therapy. In two patients in this latter group, malignancies developed in are as not usually associated with solar-induced cancer. These findings indicate that epidermal neoplasia is not uncommon in these patients and that nitrogen mustard may function as a carcinogen or a co-carcinogen.
Administration, Topical↗