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Biomedical subjects

A M Ros

Publications and source records attributed to A M Ros.

At least 19 recordsLinked to original sources
PubMed1999

Stability of 5-aminolevulinic acid in aqueous solution.

The chemical stability of 5-aminolevulinic acid (ALA) was studied in aqueous solution as a function of concentration, pH, temperature and in the presence of ethylenediaminetetraacetic acid (EDTA). The degradation of ALA was followed by reversed-phase liquid chromatography using a pH where ALA is protonated (pKa1=3.90; pKa2=8. 05, as determined potentiometrically). ALA was degraded by a reaction following second order kinetics. Stock solutions of 1% (60 mM) ALA were incubated at 50 degrees C. At pH 2.35, ALA was stable during the whole incubation period (37 days). The half-lives for the second-order decomposition of 1% ALA at pH 4.81 and 7.42 were 257 and 3.0 h, respectively. The degradation rate increased about 1.5 times with each 10 degrees C rise in temperature at pH 7.53 within the range studied (37-85 degrees C). The energy of activation, Ea, for the second-order decomposition of ALA was 43.7 kJmol-1. EDTA did not influence the degradation of ALA when a mixture of 1% ALA and 1% EDTA was incubated at pH 7.42.

Aminolevulinic Acid↗
PubMed1998

[Porphyria cutanea tarda is the most common type of porphyria. Medical control is a team work].

Porphyria cutanea tarda (PCT) is probably the most common of the porphyrias. The development of skin fragility and blisters are the symptoms that generally bring the patient to the notice of the dermatologist. During the past decade the disease has been recognised as being of heterogeneous aetiology, and a pathogenetic classification has been proposed. The significance of subtyping for the choice of management strategy is currently appreciated, as is the need of close monitoring owing to the risk of the common PCT-associated liver conditions. Preferably the PCT patient should be managed by a dermatologist and a hepatologist working in concert and supported by a specialised porphyria laboratory. The use of a structured management protocol should be considered.

Diagnosis, Differential↗
PubMed1998

[Risk of liver failure in erythropoietic protoporphyria. Be alert for sings of cholestatic development!].

Erythropoietic protoporphyria (EPP) presents clinically as a painful skin reaction to sun-light exposure. The profoundly disabling psychosocial consequences of the disease often go unnoticed by the physician, and the need to monitor the patient for hepatic complications is not generally recognised. The article describes the clinical and biochemical course in a 51-year-old man with EPP, who within a few days developed signs of acute hepatic failure. The case emphasises the importance of a well designed monitoring programme that allows close evaluation of the patient's current porphyrin metabolism, and indicates what measures should be considered.

Cholestasis, Intrahepatic↗
PubMed1998

7 years experience of photopatch testing with sunscreen allergens in Sweden.

Since 1990 7 sunscreen allergens have been included in the standard photopatch protocol at 2 Swedish dermatology clinics. 355 consecutive patients with suspected photosensitivity were tested, and in 28 of these (7.9%), a total of 42 allergic reactions were found. 80% of the reactions were of photocontact origin. The most common allergen was benzophenone-3 (Eusolex 4360), with 15 photocontact and 1 contact allergic reactions, followed by isopropyl dibenzoylmethane (Eusolex 8020) (8 photocontact, 4 contact) and butyl methoxydibenzoylmethane (Parsol 1789), with 6 photocontact reactions. There were 2 cases of photocontact allergy to phenylbenzimidazole sulfonic acid (Eusolex 232), which has not been reported previously. 1 case of contact urticaria from benzophenone-3 was accidentally found. In addition, 21 + reactions of doubtful relevance were noted in 14 patients: 16 on irradiated and 5 on non-irradiated test sites. Among these, irritant and phototoxic reactions may be included. These results indicate that the inclusion of UV filters in the standard photopatch protocol is important. Immediate-type testing for urticaria could also be of value.

Adolescent↗
PubMed1997

Occurrence of polymorphous light eruption in lupus erythematosus.

Photosensitivity is a well-known manifestation of lupus erythematosus (LE). Since there are no strict criteria for photosensitivity, varying prevalence figures have been reported. Also, distinction from polymorphous light eruption (PLE) can be difficult. The purpose of this study was to characterize photosensitivity in more detail and to determine the occurrence of PLE in a series of well-documented LE patients. A questionnaire was answered by 337 LE patients seen at dermatology departments in Finland and Sweden, and 63 of the patients were invited for interview. According to the questionnaire, LE lesions were made worse by sunlight in 242 (72%) patients. Symptoms consistent with PLE were reported by 165 (49%) patients. Detailed personal interviews supported the results from the questionnaire, and revealed that PLE had started 2-45 years before the onset of LE in 23 of 37 patients with both diagnoses, and more than 7 years before in 18 of 37 (49%). PLE proved to be common in patients with both systemic and cutaneous LE. The two conditions may often coexist and, in about half of the cases, PLE preceded LE. These two diseases may share pathogenic factors. PLE might predispose to LE in a subgroup of PLE patients.

Adolescent↗
PubMed1997

The treatment of port-wine stains with the pulsed dye laser at 600 nm.

The standard wavelength in the treatment of port-wine stains (PWS) with the pulsed dye laser is 585 nm. In many cases, the response to therapy is not adequate despite many treatments, depending partly on vessels out of reach of the laser. Longer wavelengths penetrate deeper into the dermis, but are absorbed less by oxyhaemoglobin, and require higher fluences. In this study, 22 patients with PWS were treated with the flashlamp-pumped pulsed dye laser using two different wavelengths, 585 and 600 nm. Four adjacent sites with PWS were treated on one occasion with 585 nm, 600 nm and equal fluence, and with 1.5 and 2 times the 585 nm fluence. The test areas were examined blindly, by four evaluators, an average of 12.5 weeks later. There was significantly less lightening with 600 nm than with 585 nm (P < or = 0.001) when equal fluences were used. When 1.5 and 2 times the 585 nm fluence were applied, with 600 nm the lightening was equal to that after 585 nm. However, in individual cases (11 of 22) 600 nm showed a superior lightening of at least 20% compared to 585 nm. There was slight hyperpigmentation and hypopigmentation, but no atrophy or scarring. In conclusion, 585 nm remains the wavelength of choice in treatment of PWS with the pulsed dye laser. However, in cases that do not respond satisfactorily with 585 nm, it may be worth trying 600 nm with a fluence that is at least 1.5-2 times the 585 nm fluence.

Adolescent↗
PubMed1997

Photosensitivity in lupus erythematosus, UV photoprovocation results compared with history of photosensitivity and clinical findings.

Photosensitivity, one of the presenting symptoms in lupus erythematosus (LE), is still poorly defined and varying prevalence figures have been reported. The possibility of a coexisting photodermatosis, especially polymorphous light eruption (PLE), has often not been taken into account. We report the results of ultraviolet A (UVA) and B (UVB) photoprovocation tests in 67 clinically photosensitive patients who had confirmed discoid LE (DLE), systemic LE (SLE) or subacute cutaneous LE (SCLE). The results are compared with a detailed history of photosensitivity and with clinical and serological findings. A pathological photoprovocation reaction, graded as weak, moderate or strong, was induced with either UVA or UVB in 69% of patients with LE, in 100% of those with SCLE, in 70% of those with SLE and in 64% of those with DLE, but in none of 14 controls. Only 16% of the pathological reactions were strong and long-lasting, resembling LE lesions, while 48% were moderate or weak and transient, clinically like PLE. Fifty-three per cent of the provocation reactions which were biopsied showed a PLE-like histology or a non-specific inflammatory reaction, and most of them were clinically moderate or weak reactions of short duration. In the remaining, mostly clinically strong or long-lasting reactions, the histology was consistent with LE. A history of sunlight sensitivity did not predict a pathological photoprovocation result but a positive association between the presence of SSA/Ro or SSB/La antibodies and a pathological photoprovocation reaction was found. We have shown that PLE coexists with LE and that both PLE- and LE-like lesions can be induced with UV radiation in LE patients.

Adolescent↗
PubMed1996

Psoriasis response to the pulsed dye laser.

BACKGROUND AND OBJECTIVE: In psoriasis the blood vessels are enlarged and dilated. These vessels, the psoriatic microvasculature, have been implicated as participating in the pathogenesis of psoriasis. The purpose of this preliminary study was to use the flash-lamp-pumped pulsed dye laser, which selectively damages dermal vessels, to treat psoriatic plaques and to evaluate the role of the vasculature in the therapeutic response. MATERIALS AND METHODS: Ten patients with psoriasis were treated with the pulsed dye laser on single, stable psoriasis plaques. Treatments varied between one and three times, and the lesional response was graded using a scale for erythema, scaling, and infiltration. RESULTS: Six of 10 patients experienced a beneficial clinical effect after therapy. The psoriasis severity scale in these patients was reduced to 2.2 +/- 1.3 compared with a 7.2 +/- 1.7 grade for control areas. The plaques readily developed crusting with therapy, with one leg lesion healing with atrophy. Histopathology in three patients immediately after therapy showed no epidermal damage. One week after laser therapy, the necrotic former epidermis was apparent in superficial crusting. Epidermal thinning and regeneration was seen without any signs of psoriasis. CONCLUSIONS: Pulsed dye laser therapy may improve plaque psoriasis. This improvement may be related to the role the microvasculature plays in psoriasis.

Adult↗
PubMed1996

Compositae allergy.

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Dermatitis, Allergic Contact↗
PubMed1994

Food-induced increase in bioavailability of 5-methoxypsoralen.

5-Methoxypsoralen (5-MOP) in combination with ultraviolet light exposure is used for the treatment of psoriasis. The effect of food on the pharmacokinetics of 5-MOP was evaluated in a randomized, crossover study in nine healthy subjects. Each subject received the tablets with a standardized breakfast or under fasting conditions. The food had a dramatic effect on the bioavailability of 5-MOP. Five of the subjects showed no measurable quantities (detection limit of the analytical technique 1 ng.ml-1) of 5-MOP when the drug was given under fasting conditions. However, plasma peak concentration within the range 37-144 ng.ml-1 (median 102 ng.ml-1) was measured when the drug was taken with food. The time for the plasma peak concentration was within the range 2.0-5.1 h (median 3.0 h) under non-fasting conditions. The elimination half-life was within the range 1.4-2.7 h (median 1.9 h). We conclude that it is imperative that 5-MOP tablets are administered together with food.

5-Methoxypsoralen↗
PubMed1994

Ultraviolet A phototherapy and trimethylpsoralen UVA photochemotherapy in polymorphous light eruption--a controlled study.

Twenty-two patients with polymorphous light eruption were prophylactically treated with ultraviolet A (UVA) with and without trimethylpsoralen in the first randomized double-blind study in this subject. Twelve of the patients were treated during 2 consecutive springs with placebo during one spring and psoralens during the other. Eighteen of the patients improved after the therapy, but there was no clear-cut difference between the 2 regimens. As many as 12 patients got light eruptions during the treatment, but all but one continued with the therapy. This study indicates that UVA alone is as good prophylactic therapy for polymorphous light eruption as PUVA with trimethylpsoralen. However, because of the high incidence of provoked eruptions during therapy, the treatment may be difficult to handle for the patients themselves, at least during the initial treatment.

Adult↗
PubMed1994

Treatment of psoriasis with psoralens and ultraviolet A. A double-blind comparison of 8-methoxypsoralen and 5-methoxypsoralen.

Thirty-eight patients with plaque-type psoriasis were enrolled in a double-blind psoralen plus ultraviolet A (PUVA) treatment study comparing the efficacy and side effects of 5-methoxypsoralen (5-MOP) and 8-methoxypsoralen (8-MOP). Patients treated with 8-MOP healed significantly faster than those on 5-MOP for 6 weeks of treatment, but there was no significant difference after 9 weeks. There was no significant difference in side effects between the two groups, but nausea tended to be more common in the 8-MOP group. One patient on 5-MOP had signs of toxic hepatitis. The importance for maximizing absorption of taking 5-MOP with food is stressed, and PUVA treatment should be given 3 h after intake of the drug.

5-Methoxypsoralen↗
PubMed1993

Expression of intercellular adhesion molecule-1 (ICAM-1) and OKM5 in UVA- and UVB-induced lesions in patients with lupus erythematosus and polymorphous light eruption.

Pathological skin reactions were induced with both UVA and UVB in 12 patients with lupus erythematosus (LE) and with UVA in 7 with polymorphous light eruption (PMLE) but in none of the controls. Biopsy specimens taken from UV-induced lesions showed that in dermal infiltrates of LE cases CD4-positive cells predominated, whereas in the majority of PMLE cases CD8-positive cells predominated. Keratinocytes expressed intercellular adhesion molecule-1 (ICAM-1) in 7 of the 12 UVA- and in eight of the ten UVB-induced LE lesions, and in three of the UVA-induced lesions of PMLE patients. Three different staining patterns were found. In subacute cutaneous LE (SCLE) cases staining throughout the epidermis resembled that seen in genuine SCLE lesions. In discoid LE (DLE) lesions, the staining was most prominent in and near the basal cell layer. In the one systemic LE case and in the PMLE cases, ICAM-1 expression was seen only in association with epidermal spongiosis and T-cell infiltration. Keratinocytes did not express ICAM-1 in the controls or in the non-irradiated skin of the LE patients. In five on the UVA-induced lesions, in eight of the UVB-induced LE lesions and in one of the PMLE cases, keratinocytes expressed CD36. In four of the six LE lesions with fewer CD1a-positive cells, dendritic CD36-positive cells were seen in the epidermis. In conclusion, the pattern of activated keratinocytes and immunocompetent cells in the dermis was similar to that seen in genuine LE and PMLE lesions, but dissimilar to each other and to the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Sensitivity to UV light during treatment with chloroquine in rheumatoid arthritis.

Chloroquine and hydroxychloroquine have long been suspected of causing light sensitivity in patients with rheumatoid arthritis (RA). To gain insight into the effect of chloroquines and ultraviolet (UV) light in RA we have phototested 25 RA patients with and without chloroquine. The thresholds for UVA and UVB did not change upon treatment with chloroquine or hydroxychloroquine. Provocation with high dose UVA and UVB was similar with and without treatment with chloroquine or hydroxychloroquine. Our results have shown that photosensitivity during medication with chloroquine and hydroxychloroquine is uncommon and that there is no need to stop this treatment due to sun exposure.

Adult↗
PubMed1992

Photosensitive psoriasis.

Photosensitive psoriasis is rare. The prevalence among psoriasis patients was estimated to be 5.5%. Photosensitive psoriatics have a statistically significant higher frequency of skin type I, a heredity of photosensitivity, advanced age, and psoriasis affecting hands compared with nonphotosensitive psoriatics. Half of the patients with photosensitive psoriasis have polymorphous light eruption (PLE), with psoriasis appearing as a secondary phenomenon in the PLE lesions. The other half slowly develop psoriasis after sun exposure but without preceding PLE. These reaction patterns may be confirmed with phototesting. Photochemotherapy is effective treatment for photosensitive psoriasis.

Humans↗
PubMed1990

Contact allergy to Compositae plants in patients with summer-exacerbated dermatitis.

16 patients with summer-exacerbated dermatitis were examined by patch testing and photopatch testing with a battery of Compositae and standard allergens. IgE and RAST, and the thresholds to UVA and UVB, were determined. 6 female and 2 male patients showed allergic contact reactions to one or more Compositae extracts from flowers common in Sweden, also used in skin care products. The study points to the importance of including testing with Compositae allergens in patients with summer-exacerbated dermatitis. This group comprises patients with multiple contact reactions, photosensitivity and flares of atopic dermatitis.

Adult↗