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Biomedical subjects

M Bruze

Publications and source records attributed to M Bruze.

At least 19 recordsLinked to original sources
PubMed1995

Biomonitoring of 4,4'-methylene dianiline by measurement in hydrolysed urine and plasma after epicutaneous exposure in humans.

Five healthy volunteers were dermally exposed for 1 h to 0.75-2.25 mumol 4,4'-methylene dianiline (MDA) dissolved in isopropanol, by use of a patch-test technique. Determination of MDA remaining in the patch units after exposure showed that a median of 28% (range 25-29%) was absorbed. By analysis of hydrolysed plasma, an initial accumulation of MDA could be shown, and then a decline. MDA was also detected in hydrolysed urine. The maximum rate of MDA excretion in urine was found 6-11 h after the onset of exposure. Within two subjects studied at three doses, the urinary excretion was proportional to the exposure. The elimination half-lives (elim-t1/2) in plasma and urine had medians of 13 and 7 h, respectively. In eight out of nine exposures, the elim-t1/2 was longer in plasma than in urine. Slow acetylation seemed to be associated with short elim-t1/2 in urine. The median of total MDA amount excreted in urine during 48 h, was 33 nmol for the five subjects exposed to 0.75 mumol, which corresponded to roughly 16% (range 2%-26%) of the absorbed dose while only a limited number of individuals were studied, the data still indicated that MDA in hydrolysed plasma or urine can be used for biological monitoring of occupational dermal exposure. However, the individual variation must be taken into account. Sampling should preferably be made several hours post shift. Urine is preferred before plasma at low exposures, because of its higher concentrations of MDA.

Acetylation↗
PubMed1995

Contact allergy to allyl glycidyl ether present as an impurity in 3-glycidyloxypropyltrimethoxysilane, a fixing additive in silicone and polyurethane resins.

We present a 43-year-old man who worked in the plastics industry and who suffered from an occupational dermatitis on the hands and forearms. He was found to be allergic to an epoxy silane compound that was contaminated with allyl glycidyl ether, a reactive epoxy diluent. HPLC analysis and patch testing indicated that this impurity was probably the only sensitizer. Moreover, the gloves used provided absolutely no protection, as the inner side also generated strong positive reactions.

Adult↗
PubMed1995

A study on expert reading of patch test reactions: inter-individual accordance.

To diagnose allergic or irritant contact dermatitis, a clinically relevant contact allergy has to be demonstrated or ruled out, respectively. Although patch testing has been used for 100 years, it remains the method of choice for diagnosing contact allergy. A disadvantage of patch testing is that reading is subjective, based on inspection and palpation of the test area, implying that the assessment is subject to the reader's knowledge and experience. This study was carried out to investigate the accordance in reading patch test reactions between 5 dermatologists. 4 groups, each with 10 patients, participated. Within each group, all 10 were allergic to one and the same sensitizer; nickel, epoxy resin, ethylenediamine, or Kathon CG. The sensitizers were tested in serial dilutions and applied randomly to the back. The tests were read independently by the dermatologists in a blinded fashion. A protocol was used where the dermatologists had to note the presence of the morphological features erythema, infiltration, papules, vesicles, and bullae. In this way, it was possible to allocate the various readings into 4 classification systems, 3 European and one American, although the definition of the various classifications might differ slightly. Based on the readings and classifications, it was possible to calculate the degree of accordance within the 4 systems used. It was also possible to analyze the degree of accordance for the various morphological features. Total accordance for the 5 reading dermatologists for positive and negative test reactions was noted in 36% and 46%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Occupational allergic contact dermatitis from ethyl cyanoacrylate.

Glues based on cyanoacrylates are widely used as contact adhesives for metal, glass, rubber, plastics and textiles, as well for biological materials, including binding tissues and sealing wounds in surgery. In this paper, an apprentice cobbler with an occupational allergic contact dermatitis from an ethyl cyanoacrylate glue, in which the major monomer was shown to be the sensitizer, is reported. Initial patch testing with the cyanoacrylate glue dissolved in acetone with the Finn Chamber (aluminium) technique yielded false-negative reactions. Positive test reactions were obtained with the same preparations using Van der Bend chambers. With petrolatum as vehicle for the glue, there was no difference between Finn Chamber technique and Van der Bend chamber technique. The role of aluminium in the false-negative reactions is discussed.

Abdomen↗
PubMed1995

The influence of patch tests with clobetasol propionate on adjacent patch test reactions.

Contact allergy to corticosteroids now seems frequent among patients being patch tested. As corticosteroids are intrinsically anti-inflammatory, we investigated whether patch tests with a potent corticosteroid might suppress simultaneous adjacent patch test reactions to another allergen. Nickel-sensitive subjects were patch tested with an aqueous dilution series of nickel in duplicate, adjacent to patch tests with clobetasol propionate 1% in ethanol and with ethanol, respectively. Statistical evaluation of the results obtained in 2 different centers, using their own patch test techniques, did not reveal any suppression of the positive nickel patch test reactions.

Clobetasol↗
PubMed1995

Skin testing with gold sodium thiomalate and gold sodium thiosulfate.

Recently gold sodium thiosulfate was found to be the most common sensitizer after nickel sulfate in our routinely patch tested dermatitis patients. When patients hypertensive to gold sodium thiosulfate were tested with another monovalent gold salt, gold sodium thiomalate, at equimolar concentrations, in principle, no positive reactions were obtained. Gold sodium thiomalate is used for treatment of rheumatoid arthritis, a treatment with a high frequency of adverse skin reactions. To investigate whether the reactivity difference between the 2 gold salts was due to differences in bioavailability, some experiments were carried out. Intracutaneous tests with the 2 gold salts at equimolar concentrations yielded equivalent reactions. When the concentration of gold sodium thiomalate for epicutaneous testing was increased, all 12 gold-allergic patients reacted positively. Therefore, in our department, contact allergy to gold sodium thiomalate is probably as common as contact allergy to gold sodium thiosulfate.

Administration, Cutaneous↗
PubMed1995

Occupational allergic contact dermatitis from alkanolamineborates in metalworking fluids.

Alkanolamineborates are extensively used in coolants as corrosion inhibitors. In this paper, 3 machinists with contact allergy to alkanolamineborates are reported. To avoid false-positive test reactions due to the alkalinity of the alkanolamineborates, they should be tested when dissolved in an acidic buffer. When various alkanolamineborates were tested in dilution series in the 3 patients, 2 types of reactivity patterns emerged, indicating the existence of at least 2 separate sensitizers in alkanolamineborates. The raw materials, ethanolamines and boric acid, did not yield any positive patch test reactions. Thin-layer chromatography investigations demonstrated that each alkanolamineborate consists of many substances, which differed in part between different alkanolamineborates. The present study shows that it is not possible to use 1 particular alkanolamineborate for tracing contact allergy to alkanolamineborates in general.

Adult↗
PubMed1995

[Improved management of allergic contact eczema].

Allergic contact dermatitis (ACD) is common. Its diagnosis requires patch testing to establish ACD, followed by repeat open application testing (ROAT) to confirm that the putative allergen is in fact responsible for the ACD. The aim of primary management is to eliminate or minimise exposure to the allergen and its cross reactants. To promote healing and ease discomfort, local treatment is given, which in principle always consists of a short course of corticosteroids and an emollient. Sometimes antibiotics may be necessary, as well as systemic corticosteroid treatment for a brief period. In cases of persistent ACD, and sometimes in cases with a multifactorial background, further treatment may be required, first and foremost phototherapy. In isolated cases, treatment with low-energy roentgen (grenz rays), retinoids or cyclosporine may be called for. Desensitisation is not possible, and at present treatment with chelating agents and diet has no place in the management of ACD.

Administration, Topical↗
PubMed1994

Clinical relevance of contact allergy to gold sodium thiosulfate.

BACKGROUND: In our routinely patch tested patients with dermatitis gold was shown to be the second most common sensitizer. In most patients it was difficult to explain the source of sensitization to gold and to see any clinical relevance. OBJECTIVE: Our purpose was to elucidate the clinical relevance of contact allergy to gold sodium thiosulfate. METHODS: A questionnaire on gold exposure and gold sensitivity was answered by 156 consecutive patients with dermatitis. In another group of 1056 routinely tested patients data were collected and analyzed regarding factors such as profession, atopy, localization of the dermatitis, and presence of contact allergies. RESULTS: Gold allergy was overrepresented in those having dental gold. In persons with contact allergy to gold a dermatitis on the ears, fingers, or eye area was most frequent. CONCLUSION: Exposure to gold jewelry and to dental gold may be important in the sensitization and elicitation of dermatitis.

Allergens↗
PubMed1994

Systemically induced contact dermatitis from dental rosin.

Rosin is a ubiquitous contact sensitizer which may be present in dental materials such as periodontal dressings, impression materials, cements, and cavity varnishes When a hypersensitive person is exposed to a sensitizer, allergic contact dermatitis/stomatitis may develop, most commonly after direct skin/mucosa contact with the sensitizer. However, widespread dermatitis may develop after systemic administration of the sensitizer, and this paper reports the case of a rosin-hypersensitive man who developed widespread eczematous dermatitis after dental treatment with a rosin-containing product.

Balsams↗
PubMed1994

Quinine and quinidine photoproducts can be identical.

Quinine and its d-isomer quinidine can both cause contact allergy as well as photoallergy. Contact allergic cross-reactions between quinine and quinidine are uncommon. In allergic photosensitization the two isomers cross-react, suggesting the possibility that quinine and quinidine after UV exposure are converted to one or more common sensitizing photoproducts. Solutions of quinine and quinidine at 0.1% in ethanol 99.5% were exposed to UVA for 14 h (total dose 201.6 J/cm2). Using thin-layer chromatography, we identified 8 and 6 photoproducts from irradiated quinine and quinidine, respectively. Five of these photoproducts were seen in both chromatograms. An identical pattern with four photoproducts was found for both irradiated solutions when these were subjected to analysis in a high-performance liquid chromatography system. This study indicates that photoproducts from irradiated quinine and quinidine can be identical. This would explain the differences in the cross-reactivity pattern between contact and photocontact sensitization clinically.

Chromatography, High Pressure Liquid↗
PubMed1994

Dermatitis with an unusual explanation in a welder.

Occupational diseases among welders include asthma, acute keratoconjunctivitis, and various skin disorders. A localized cutaneous erythema from UVC radiation is common and does not generally constitute any problem, as its cause is obvious to the welder, the symptoms are slight, and it is transient. In this report a welder with UVC-induced erythema on the cheeks is described. Initially, neither the worker, the physician at the factory, nor ourselves suspected a UVC erythema. Extensive investigations, including factor visits with measurements of UVA, UVB, and UVC irradiance during welding, revealed the cause of the dermatitis to be UVC, most likely reflected from a textile hood used to prevent exposure to dirt.

Adult↗
PubMed1994

The histological and immunohistochemical pattern of positive patch test reactions to gold sodium thiosulfate.

Gold sodium thiosulfate, inserted in the patch test standard series, gives a surprisingly high yield of positive reactions, about 10% of tested eczema patients, but with a low degree of clinical relevance. A histopathological study on patch test reactions was carried out in patients selected because of a combined contact allergy to gold sodium thiosulfate and nickel. Biopsies were taken from macroscopically similar reactions in dilution series of each allergen. The histological picture was clearly eczematous, without irritative features. In a blind comparison, test reactions induced by the two allergens could not be differentiated from each other. Long-lasting patch test reactions to gold sodium thiosulfate were characterized by an intense lymphocytic dermal infiltrate without epidermal involvement. Immunohistochemically, CD4+ and CD8+ T lymphocytes could be detected already 4-8 h post-challenge, and "naive" as well as "memory"-type T cells were demonstrated. Apparently, our findings reflect a true contact allergy to gold sodium thiosulfate.

Adult↗