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Biomedical subjects

P Lehmann

Publications and source records attributed to P Lehmann.

At least 19 recordsLinked to original sources
PubMed1992

Photosensitivity induced by quinidine sulfate: experimental reproduction of skin lesions.

A case of quinidine sulfate-induced photodermatitis is reported. The photosensitive reaction to quinidine sulfate was reproducible in the photopatch test and after oral intake plus ultraviolet A (UVA) irradiation. Eczematous dermatitis was provoked after intradermal injection of in vitro UVA-irradiated quinidine sulfate only in the presence of patient's serum. The clinical picture and histology suggest an allergic reaction. The photobinding of quinidine sulfate to a potential carrier protein in skin or serum seems to be of crucial importance for this type of photodermatitis. Quinidine sulfate is frequently used as an antiarrhythmic drug. Its potential as a photosensitizer should always be considered.

Aged↗
PubMed1992

Results of the multicenter evaluation of the CEDIA Phenytoin assay.

Thirteen clinical evaluation sites in Europe and U.S.A. investigated the CEDIA Phenytoin assay on Boehringer Mannheim/Hitachi analyzers with respect to imprecision, recovery of control sera, interlaboratory survey, linearity and method comparisons using patient samples. The linear dose-response relationship up to 40 micrograms/mL was confirmed by all participants. Imprecision at therapeutic analyte concentrations equalled that of other routine methods. Recovery of controls was found in a +/- 6% range for target values assigned by the CEDIA assay. The good interlaboratory transferability of the CEDIA assay was confirmed with control material and human samples. The reconstituted reagent can be used up to one month using weekly recalibration. In method comparison studies good correlations to other routine methods were obtained. Results in analyte-free human sera did not deviate systematically from the zero-point. Thus, the accuracy in patient sera has been shown for the CEDIA Phenytoin assay.

Dose-Response Relationship, Drug↗
PubMed1992

Results of the multicenter evaluation of the CEDIA Phenobarbital assay.

The CEDIA Phenobarbital assay has been evaluated in twelve clinical laboratories in Europe and U.S.A. on Boehringer Mannheim/Hitachi analysis systems. The evaluation focused on the analysis of imprecision and accuracy. Within-run and between-day coefficients of variations of the new assay were comparable to those of established routine methods. As demonstrated in an interlaboratory survey study with controls and human sera, results obtained in different laboratories showed a good agreement. The CEDIA Phenobarbital assay measured very accurately, as particularly confirmed by comparison with HPLC. It can be recommended as a reliable and practicable test for monitoring of phenobarbital on Boehringer Mannheim/Hitachi analyzers used in routine clinical chemistry.

Calibration↗
PubMed1992

[The effect of UV-A and UV-B irradiation on the skin barrier. Skin physiologic, electron microscopy and lipid biochemistry studies].

In order to gain insight into the effects of UV-irradiation on the skin barrier, functional (skin reactivity), electron microscopic and lipid-biochemical studies were performed. In three different irritation models, both UV-A-irradiated and UV-B-irradiated areas proved to be more resistant to damage than normal skin, providing evidence for improvement of barrier function after UV irradiation. Electron microscopic evaluation showed that UV-B induced a significant increase in horny cell layers, whereas after UV-A no change was detected. However, both UV-B and UV-A exposure resulted in an increase in the amount of all stratum corneum lipids. This was also observed in all major ceramide subfractions, which are believed to be the essential lipid constituents for the epidermal barrier function. These findings may explain the known beneficial effects of phototherapy in dermatoses with impaired barrier function, i.e., atopic dermatitis.

Dose-Response Relationship, Radiation↗
PubMed1991

Influence of UV irradiation on the composition of human stratum corneum lipids.

Irradiation with suberythemal doses of either UV-A or UV-B yielded an increase in the amount of stratum corneum lipids extracted from the lumbar skin area of 20 volunteers. These lipids were quantified after separation by high-performance thin-layer chromatography. Ten subfractions in the ceramide region were separated; two of them (fractions 7a and 7b) were only detectable after UV-A or UV-B irradiation. Improvement of barrier function after UV irradiation of human skin with suberythemal doses may be related to an increase in the stratum corneum ceramides.

Adult↗
PubMed1991

[Chronic actinic dermatitis. Concept and case examples].

Two women patients with chronic eczematous dermatitis, who also developed extremely severe, persistent photosensitivity during a course of 10 and over 40 years, are presented. Both patients had an atopic history with positive immediate skin reactions. Patch and photopatch tests revealed sensitization to several contact allergens, and in one case also a photocontact allergy. The action spectrum of the photosensitivity was confined to UV-B; it was possible to provoke eczematous skin reactions with doses smaller than 1 mJ/cm2 UV-B. Both patients were successfully treated with PUVA therapy. These case reports demonstrate the difficulty of nosological classification of chronic eczematous photosensitive dermatoses under the traditional terms persistent light reaction, photosensitive eczema, photosensitivity dermatitis, and actinic reticuloid. Chronic actinic dermatitis is defined clinically by chronic dermatitis on skin exposed to sun, histologically by spongiotic dermatitis, and photobiologically by experimental provocation of spongiotic dermatitis with UV-B and often also longer wavelengths in the absence of a photoallergen. Chronic actinic dermatitis should be used as a general term in addition to the more specific terms listed above.

Biopsy↗
PubMed1991

Effects of ultraviolet A and B on the skin barrier: a functional, electron microscopic and lipid biochemical study.

To investigate the effects of ultraviolet A (UVA) and B (UVB) on the skin barrier, functional, electron microscopic and lipid biochemical studies were performed on normal and UV-irradiated skin of volunteers. Skin reactivity against primary irritants was evaluated using the alkali resistance test, the dimethylsulfoxide test and the sodium lauryl sulfate test. In all 3 irritation models, UVA- and UVB-irradiated areas were more resistant to damage than normal skin, indicating improvement of the barrier function after UV irradiation. In a second series of experiments, biopsies were taken and processed for electron microscopic evaluation of the stratum corneum. UVB significantly increased the horny cell layers; UVA did not alter the thickness of the stratum corneum. Finally, stratum corneum lipids were extracted in vivo and quantified after high-performance thin-layer chromatography. UVB and, to some extent, UVA exposure increased the amount of all stratum corneum lipids. This was also observed in all major ceramide subfractions.

Adolescent↗
PubMed1991

[Quinidine-induced photoallergy. A clinical and experimental study].

Photoallergies are type-IV allergic reactions of a special kind. Photoallergies due to quinidine sulphate were described as early as 1942. We present a case of quinidine sulphate-induced photodermatitis. The photoallergic reaction to quinidine sulphate was reproducible not only after oral intake but also in the photopatch test. In addition, an eczematous dermatitis was provoked after intradermal injection of quinidine sulphate previously exposed to UV-A irradiation in vitro together with serum taken from the patient. No dermatitis was seen with quinidine sulphate irradiated in the absence of serum. The binding of the hapten quinidine sulphate to a potential carrier protein in the serum seems to be of crucial importance in this type of photodermatitis. Quinidine sulphate is frequently used as an antiarrhythmic drug. Its potential photoallergenic action should always be considered.

Aged↗
PubMed1991

[Erythropoietic protoporphyria: synopsis of 20 patients].

The authors present 20 patients (9 men, 11 women) with erythropoietic protoporphyria (EPP). The diagnosis was made on the basis of photosensitivity and porphyrin analysis. The disease first became apparent in the first years of life. The following acute symptoms were induced after exposure to sunlight: pruritus with or without skin changes, burning, pain and erythema, sometimes with petechiae, vesiculation and, in two cases, systemic symptoms. Chronic skin changes included hyalinosis cutis-like skin lesions, scarring, and also petechiae. Phototesting provoked only subjective symptoms, and none of the skin lesions characteristic of EPP could be induced. Postnatal diagnosis was attempted in three newborns, each of whom had one parent with proven EPP, by measuring the porphyrins in erythrocytes of cord blood. In all three normal porphyrin values were determined, and during an observation period of 3 years none has developed EPP. Therapy with carotenoids has yielded good to very good results in two-thirds of the patients. So far, a diagnosis of EPP has been established in 30 patients in Düsseldorf: one has died of liver cirrhosis and another has liver damage.

Adolescent↗
PubMed1990

Experimental reproduction of skin lesions in lupus erythematosus by UVA and UVB radiation.

Sunlight is a well-established factor in the induction and exacerbation of lupus erythematosus. Although experimental reproduction of lupus erythematosus lesions with wavelengths shorter than 320 nm was demonstrated previously, the effect of wavelengths longer than 320 nm was not investigated adequately. In this study we show that the action spectrum of lupus erythematosus reaches into the UVA region. A total of 128 patients with lupus erythematosus underwent phototesting with the use of polychromatic UVB and long-wave UVA. Subsets of the disease consisted of discoid lupus erythematosus (n = 86), subacute cutaneous lupus erythematosus (n = 22), and systemic lupus erythematosus (n = 20). Skin lesions clinically and histologically compatible with lupus erythematosus were induced in 64% of patients with subacute cutaneous lupus erythematosus, 42% of patients with discoid lupus erythematosus, and 25% of patients with systemic lupus erythematosus. The action spectrum of the induced lesions was within the UVB range in 33% of patients, in the UVA range in 14%, and in the UVB and UVA range in 53%. In positive test reactions patchy dark erythema and urticarial plaques developed within a few days. In some patients typical discoid lesions persisted for months.

Adolescent↗
PubMed1990

Health and social inequities in Switzerland.

Despite standards of living and life expectancy amongst the highest in Europe, Switzerland exhibits fairly substantial social inequities in health. As regards male mortality by socio-economic group, these differentials are both marked and independent of cause of death. There is a wealth of information on morbidity and disability supporting the hypothesis that people in lower socio-economic groups tend to age faster and suffer more at younger ages. It is similarly evident that infants of low class mothers, particularly those unwed, underprivileged immigrant, are at excess risk. The Swiss results are of political and scientific interest in that they suggest that the average wealth of a community does not determine health differentials.

Adolescent↗
PubMed1990

Preliminary characterization of the repeated DNA sequence from Vicia sativa.

We have identified a family of interspersed repeated sequences present in about 40,000 copies in the genomes of Vicia sativa and its near relative Vicia faba. The element vif is at least 6 kb in length, and members of the repeat family display a degree of heterogeneity in restriction pattern. Homologous elements in V. faba are much more heterogeneous than their V. sativa counterparts; however, analysis of five different V. faba lines revealed substantially the same patterns, suggesting that this family was reamplified prior to the divergence of the lines studied.

Cloning, Molecular↗
PubMed1990

[Photobiology of lupus erythematosus].

Photosensitivity is one of the criteria of the American Rheumatism Association for the diagnosis of systemic lupus erythematosus. Although UV irradiation is a major factor in the pathogenesis of photosensitive cutaneous lupus erythematosus, so far the exact pathomechanism is unknown. The following review presents historical, clinical and experimental data on the photobiology of cutaneous lupus erythematosus.

Animals↗
PubMed1990

[A new fructosamine test--as a routine parameter in the control of diabetes].

Measurement of protein glycation (fructosamine) has become an accepted tool in diabetes diagnostics. Among different methods available, the serum fructosamine test published by Johnson and Baker in 1983 has gained wide acceptance due to a simple and easily automated assay procedure providing clinically meaningful results. A recent modification of the Nitroblue Tetrazolium (NBT) reagent, improved by addition of tensides and uricase, exhibits lower interference by lipaemia and urate. It is also less affected by the sample matrix and yields results closer to the physiological range of glycated proteins. Furthermore, a completely new standardization protocol was used in the preparation of calibration material. The new colorimetric method for the determination of fructosamine was evaluated in 12 European clinical laboratories.

Blood Glucose↗
PubMed1990

[Lupus erythematosus].

Our paper summarizes the clinical and photobiological studies on lupus erythematosus (LE) performed at the Department of Dermatology, University of Düsseldorf, during the last 5 years. A total of 190 LE cases were examined and classified according to the various cutaneous forms of LE. Except for lupus erythematosus tumidus (LET), we found a female predominance in all other groups. Discoid lupus erythematosus (DLE) is the most common variant of cutaneous LE. Subacute cutaneous lupus erythematosus (SCLE), a less common type, is characterized by the presence of Ro-antibodies, although this marker does not correlate with the degree of photosensitivity. The rare LET is an extremely photosensitive form of LE, which clearly prefers the male sex.

Adolescent↗