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Biomedical subjects

W Frain-Bell

Publications and source records attributed to W Frain-Bell.

At least 19 recordsLinked to original sources
PubMed1989

A study of persistent photosensitivity as a sequel of the prior administration of the drug benoxaprofen.

Cutaneous photosensitivity is a recognized side-effect of a number of commonly used groups of drugs, among which are the non-steroidal anti-inflammatory agents (NSAIDs) one of which, benoxaprofen, was withdrawn from use in 1982. The abnormal reaction of the skin to light usually occurs during the period of the systemic administration of the drug, but may with some drugs persist for longer, even for months. Chronic photosensitivity, i.e. 'persistent light reaction' of some years duration, continuing after the withdrawal of the primary cause, has so far only been reliably reported when the initial exposure of the skin to the photoactive substance has been by external contact and not following ingestion. A suggestion that photosensitivity could persist for a period of years as a sequel of initial benoxaprofen-induced photosensitivity was studied in a group of 42 subjects said to be affected in this way. The results failed to confirm the presence of persistent photosensitivity. It appeared that the probable explanation for the episodic abnormal reactions to light over the years since 1982 was the systemic administration of other photoactive drugs including a series of NSAIDs.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1987

Thiazide-induced photosensitivity: a study of 33 subjects.

The clinical features, action spectrum and subsequent course, are described in 33 subjects with thiazide-induced photosensitivity. The reaction appeared to be phototoxic in nature. The wavelengths involved were those of the longer UVA and, not infrequently, also the shorter UVB waveband. In most instances withdrawal of the drug resulted in clearance of the clinical reaction and a return of the action spectrum to normal. In the few subjects in whom the photosensitivity persisted, either in the form of the clinical reaction or an abnormal action spectrum, or both, either a specific photodermatosis was present or another potentially photoactive drug was being taken. In no instance, was there evidence of the induction of long-term chronic photosensitivity (persistent light reaction) following the withdrawal of the thiazide drug.

Aged↗
PubMed1987

Quinine induced photosensitivity: clinical and experimental studies.

Quinine induced photosensitivity, an infrequently described adverse effect, is reported in four patients. The clinical presentation and distribution was that of a light exposed site eruption characterized by oedema and erythema in three patients, and by lichen planus in the fourth. Monochromator phototesting demonstrated abnormal delayed erythema responses in the UVB, UVA and visible wavebands. The clinical features suggested a phototoxic effect but laboratory studies indicated that the molecular mechanisms involved are unusual. Clinical and phototest evidence of abnormal photosensitivity persisted for some months after stopping quinine. Broad spectrum sunscreens are advised for the management of such patients and, where possible, cessation of quinine administration.

Aged↗
PubMed1985

A study of cutaneous photosensitivity induced by amiodarone.

Amiodarone-induced cutaneous photosensitivity was studied in 12 subjects treated with the drug. The action spectrum for the abnormal response to sunlight was shown to be within the range of 335-460 (+/- 30) nm. The clinical features of the photosensitivity response suggested that it was most probably a phototoxic reaction, a conclusion supported by the results of in vitro studies which indicated activity mainly against cell membranes. Of the five in vitro models used, three--namely photohaemolysis, the inhibition of DNA synthesis in PHA stimulated lymphocytes and the killing of mouse peritoneal macrophages--provided unequivocal evidence of the phototoxic potential of both amiodarone and its major metabolite, desethylamiodarone. In each model desethylamiodarone produced a greater effect by a factor of between 2 and 10. In vitro, UV-B wavelengths produced a greater effect than UVA but the difference between the effective wavelengths in vivo and in vitro might be explained by the greater absorption of the shorter wavelength UV-B in the epidermis. Zinc oxide-containing preparations appeared to be the most effective in reducing the cutaneous photosensitivity. It is suggested that the long-term cutaneous pigmentation resulting from oral amiodarone has a significant photosensitivity component.

Adult↗
PubMed1985

A study of compositae plant extract reactions in photosensitivity dermatitis.

In subjects with chronic photosensitivity of the photosensitivity dermatitis/actinic reticuloid type the persistent reaction of the skin appears to be due to a number of factors, including those of contact allergic sensitivity and of photosensitivity (i.e., phototoxicity and/or photoallergy). The assessment of the relevant importance of these factors can be complicated by the reactivity of the skin resulting in false positive responses from skin patch and photopatch testing. Moreover, difficulties may also arise in the assessment of the results using commercially available patch test materials. However, the study described here indicated that, provided the reactivity of the skin is suppressed prior to investigation, reliable results are obtained from photopatch testing and that these results are similar whether the extract is from a commercial source or has been obtained from locally grown Compositae plants. Also, that although there may be a photoallergic component in the cutaneous photosensitivity, the results of the in vivo and in vitro studies reported here indicate the likely involvement of phototoxicity as well.

Adult↗
PubMed1984

Actinic prurigo--a specific photodermatosis?

Actinic prurigo can be defined as an idiopathic photodermatosis which usually starts in childhood, particularly affects the female, with some evidence for an atopic and familial photosensitivity background. It affects both exposed and covered skin but mainly the former and although it may be present all the year round is usually maximal on the exposed skin during months of sunshine. The changes are those of a chronic prurigo along with more acute episodes following sunshine exposure in which there is a background of edematous erythema. It usually lasts throughout childhood and adolescence, but tends to wane and even to clear in late adolescence or early adult life. The etiology is unknown, as are the mechanisms involved. Action spectrum studies have produced no evidence for the involvement of specific wavelengths other than the presence of UV sensitivity in some subjects and a suggestion that the longer wavelength UVA may be more important than the sunburn waveband around 305 nm. Based on a study of 60 personal cases with actinic prurigo the authors agree with the longheld view of Calnan & Meara (1) that actinic prurigo is a separate and distinct photodermatosis.

Adolescent↗
PubMed1979

Contact allergic sensitivity to chrysanthemum and the photosensitivity dermatitis and actinic reticuloid syndrome.

Of sixty-nine examples of the photosensitivity dermatitis and actinic reticuloid syndrome, nine were found to be allergically sensitive to chrysanthemum oleoresin extract. Although this extract showed evidence in vitro of a phototoxic action we were unable with in vivo studies to explain the connection between the contact allergic sensitivity and the photosensitivity. The fractions responsible for the in vitro phototoxicity appear to be different from those involved in the in vivo contact allergic sensitivity. This study provides further support for the view that in the photosensitivity dermatitis and actinic reticuloid syndrome contact allergic sensitivity is of importance.

Aged↗
PubMed1979

Contact allergic sensitivity to plants and the photosensitivity dermatitis and actinic reticuloid syndrome.

Contact allergic sensitivity to oleoresin extracts from Compositae plants was found to be usually present in individuals suffering from the photosensitivity dermatitis and actinic reticuloid syndrome. It was demonstrated in forty-seven out of fifty-five examples of this syndrome. These results provide support for the view that contact allergic sensitivity is an important aspect of the state of chronic photosensitivity in the middle-aged and elderly male.

Adult↗
PubMed1977

Photochemotherapy in the treatment of psoriasis.

This article describes the satisfactory clinical improvement obtained in the majority of a group of 72 patients with psoriasis of various types as a result of the oral and/or topical administration of 8-methoxypsoralen followed by long wavelength ultraviolet irradiation. The irradiation source used was that of conventional longwave UV fluorescent tubes mounted in a specially constructed cubicle. Until such time as the long term effect of this form of photochemotherapy on the cell has been evaluated and the most appropriate regime worked out, it would seem to be important to restrict the amount of irradiation used to that required to produce acceptable maintained clinical improvement.

Adolescent↗
PubMed1977

A study of oil of bergamot and its importance as a phototoxic agent. I. Characterization and quantification of the photoactive component.

It is important in the technique of photopatch testing, using oil of bergamot, to have determined the concentration of the active psoralen, bergapten, so as to avoid false negative responses in the assessment of phototoxic reactions. Techniques for assessing the phototoxic components of oil of bergamot are described and quantitative analyses of bergapten, the only significant photoactive compound in the samples examined, are reported. The phototoxicity of bergapten was found to be nearly the same as that of xanthotoxin (8-MOP) in tests on human skin.

Coumarins↗
PubMed1977

Sister chromatid exchanges in lymphocytes of psoriatics after treatment with 8-methoxypsoralen and long wave ultraviolet radiation.

Sister chromatid exchange rates in cultured cells from the blood of patients receiving photochemotherapy have been examined as an indicator of possible genetic hazards of the treatment to patients with psoriasis. Lymphocytes of untreated patients with psoriasis appear to have sister chromatid exchange rates after 72 h of culture indistinguishable from normal subjects and there is no evidence from these studies that sister chromatid exchanges are significantly increased in the lymphocytes of patients receiving photochemotherapy. Cells from blood taken from patients who had been given 8-methoxypsoralen orally 2 h before and then irradiated with UV-A in vitro were found to have an increased exchange rate which could be related to the presence of the drug in the peripheral circulation.

Chromatids↗
PubMed1977

The treatment of erythropoietic protoporphyria. Experience with beta-carotene.

In a group of 19 subjects suffering from erythropoietic protoporphyria the administration of beta-carotene appeared to produce improvement based on a subjective assessment of alterations in exposure times required to produce the symptoms and signs of the condition. This clinical improvement however failed to show a direct correlation with the prophyrin levels in blood and faeces, or with the estimation by phototesting of the minimal response dose within the action spectrum of 400-600 nm.

Adolescent↗
PubMed1977

A study of oil of bergamot and its importance as a phototoxic agent. II. Factors which affect the phototoxic reaction induced by bergamot oil and psoralen derivatives.

Using a standardized open photopatch test technique, the phototoxic reactions produced by bergamot oil bergapten (5-methoxypsoralen) the active component of the oil, and xanthotoxin (8-methoxypsoralen) were studied. The reaction was affected by a range of factors such as the vehicle (PMF or ethanol), the concentration of ethanol in the vehicle, the skin site, the interval between application of the psoralen and irradiation, the hydration of the skin, and the degree of natural or sun-induced pigmentation. Repeated photopatch testing at the same skin site produced an increase in sensitivity. Eye colour, natural susceptibility to suntanning, age, and sex, had no effect on the phototoxic response to psoralens.

Adolescent↗