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Biomedical subjects

M Isaksson

Publications and source records attributed to M Isaksson.

At least 19 recordsLinked to original sources
PubMed1999

Occupational allergic contact dermatitis from olive oil in a masseur.

Contact allergy to olive oil is considered rare. There are 20 cases of contact allergy to olive oil described, and 3 of these had an occupational hand eczema as a result of olive oil. We describe a masseur who was allergic to olive oil, resulting in an occupational hand eczema. Both patch tests and a use test with olive oil was undertaken. An oral provocation with olive oil was also performed. Both patch tests were positive, as was the use test after 2 days. The oral provocation test was negative. Despite contact allergy to olive oil being rare, sensitization occurs. The external use of olive oil should be discouraged, at least in masseurs, when used under occlusion, and in long-standing dermatoses.

Dermatitis, Allergic Contact↗
PubMed1999

The benefit of patch testing with a corticosteroid at a low concentration.

BACKGROUND: Patch testing with corticosteroid marker molecules is advocated because testing with all available corticosteroids is impossible in clinical practice. Most commonly used are budesonide, tixocortol pivalate, and hydrocortisone-17-butyrate. We have been patch testing not only with the three markers, but also with two corticosteroid mixes, each consisting of different concentrations of the three markers. OBJECTIVE: We describe a patient allergic to tixocortol pivalate, who was diagnosed by using a lower patch test concentration that recommended, 0.1% in petrolatum, as well as a weak corticosteroid mix, 0.202%. METHODS: The patient was patch tested to a standard series, including the two corticosteroid mixes and its three constituents. RESULTS: None of the corticosteroid preparations were positive on the first ordinary reading day, day 3, whereas both tixocortol pivalate at 0.1% and the corticosteriod mix at 0.202% were positive on the second ordinary reading day, day 7, whereas all tested corticosteroids in the standard series gave positive reactions on d10. CONCLUSION: The possible benefit of patch testing with a corticosteroid at a low concentration is supported, as is the significance of late readings beyond D4.

Administration, Topical↗
PubMed1999

Occupational dermatoses in composite production.

In a plant that produces fiber-resin composite by impregnation of cellulose fibers with phenol-formaldehyde and melamine-formaldehyde resins, a new technique was introduced that resulted in problems in the handling of uncured products. Many workers suffered dermatitis on areas of exposed skin. A primary investigation found that some workers had an occupationally related skin disease with contact allergy to work materials. We undertook a survey of occupational dermatoses, based on a questionnaire, clinical examination, and patch test with a standard series and a series of products and chemicals representing the work environment. Eighty-eight workers participated in the clinical investigation. In six workers, contact allergy to phenol-formaldehyde resin was seen, and in five workers, contact allergy to melamine-formaldehyde resin was noted. Two workers were allergic to both resins. Occupational dermatitis was diagnosed in nine of 88 (10.2%) workers. In this article, we discuss possible preventive measures for avoiding occupational dermatitis.

Adult↗
PubMed1999

Patch testing with budesonide in serial dilutions: the significance of dose, occlusion time and reading time.

Budesonide is advocated as a marker molecule for corticosteroid contact allergy. When patch testing corticosteroids, one must consider their sensitizing potential but also their anti-inflammatory properties, as well as the possibility of different time courses for such properties. The dose-response relationship for budesonide was therefore investigated with regard to dose, occlusion time, and reading time. 10 patients were patch tested with budesonide in ethanol in serial dilutions from 2.0% down to 0.0002% with occlusion times of 48, 24, and 5 h. Readings were on D2, D4, and D7. The 48-h occlusion picked up most positive reactors, 8/10. The D4 reading (48-h occlusion) detected most positive reactors, 8/10, and here 0.002% picked up most contact allergies. Late readings favoured high concentrations. The "edge effect" was noted for several concentrations at early readings. Due to the individual corticosteroid reactivity, the dose-response relationship and the time courses of the elicitation and the anti-inflammatory capacity, several features may be explained, i.e., that lower concentrations may detect budesonide allergy better at early readings, that patients with an "edge reaction" can have positive reactions to lower concentrations.

Administration, Topical↗
PubMed1998

Contact allergy to hydrocortisone and systemic contact dermatitis from prednisolone with tolerance of betamethasone.

BACKGROUND: Contact allergy to corticosteroids is not uncommon. As the clinical pattern that the patients exhibit may be misleading, the discovery at patch testing may be unexpected and solely a result of the fact that marker molecules for corticosteroid contact allergy are incorporated into standard series and that tests are read twice, on D3/4 and D7. OBJECTIVE: We describe a patient allergic to hydrocortisone who was given a cross-reacting corticosteroid, prednisolone, that led to a systemic contact dermatitis. The patient cleared when betamethasone, a non¿Ncross-reacting corticosteroid, was administered. METHODS: The patient was patch tested to a standard series including tixocortol pivalate, and an extended corticosteroid series including betamethasone. RESULTS: Patch testing with tixocortol pivalate provoked an allergic patch test reaction (+? D3, +D7), whereas betamethasone did not. CONCLUSION: Our patient's allergy was undiagnosed for 5 years, and it was not until she was given a cross-reacting corticosteroid, which led to exacerbation of her dermatitis, that her physician suspected corticosteroid allergy. The incorporation of marker molecules for the detection of corticosteroid contact allergy into standard series with two reading occasions, 3 to 4 days apart, is advocated.

Anti-Inflammatory Agents↗
PubMed1997

Antitumor activity of carcinoma-reactive BR96-doxorubicin conjugate against human carcinomas in athymic mice and rats and syngeneic rat carcinomas in immunocompetent rats.

The internalizing monoclonal antibody BR96 was conjugated to the anticancer drug doxorubicin (DOX) using an acid-labile hydrazone bond to DOX and a thioether bond to the monoclonal antibody. The resulting conjugate, termed BR96-DOX, binds to a tumor-associated Lewis(y) antigen that is abundantly expressed on the surface of human carcinoma cells. BR96-DOX binds to RCA, a human colon carcinoma cell line, and BN7005, a transplantable colon carcinoma induced in a Brown Norway (BN) rat by 1,2-dimethyl-hydrazine. BR96-DOX produces cures of established s.c. RCA human colon carcinomas in athymic mice and rats. BR96-DOX also cured both s.c. and intrahepatic BN7005 tumors in immunocompetent BN rats. Unconjugated DOX, given at its maximum tolerated dose, and matching doses of nonbinding IgG-DOX conjugate were not active against RCA or BN7005 carcinomas. An anticonjugate antibody response was produced in BN rats treated with BR96-DOX. However, this could be largely prevented by administering the immunosuppressive drug deoxyspergualin. These results confirm the concept of antibody-directed therapy in models in which the targeted antigen is expressed both in normal tissues and tumors. The findings in BN7005 further demonstrate efficacy of BR96-DOX therapy in a model in which the tumor is syngeneic and the host is immunocompetent.

Adenocarcinoma↗
PubMed1997

Characteristic sequence motifs at the breakpoints of the hybrid genes FUS/CHOP, EWS/CHOP and FUS/ERG in myxoid liposarcoma and acute myeloid leukemia.

We have sequenced the breakpoint regions in one acute myeloid leukemia (AML) with t(16;21)(p11;q22) resulting in the formation of a FUS/ERG hybrid gene and in four myxoid liposarcomas (MLS), three of which had the translocation t(12;16) (q13;p11) and a FUS/CHOP fusion gene and one with t(12;22;20)(q13;q12;q11) and an EWS/CHOP hybrid gene. The breakpoints were localized to intron 7 of FUS, intron 1 of CHOP, an intronic sequence of ERG and intron 7 of EWS. In two MLS cases with t(12;16) and in the AML, the breaks in intron 7 of FUS had occurred close to each other, a few nucleotides downstream from a TG dinucleotide repeat region. The break in the two MLS had occurred in the same ATGGTG hexamer and in the AML 40 nucleotides upstream from the hexamer. The third case of t(12;16) MLS had a break upstream and near a TC-dinucleotide repeat region and a sequence similar to the chi bacterial recombination element was found to flank the breakpoint. In the MLS with the EWS/ CHOP hybrid gene, the break in intron 7 of EWS had occurred close to an Alu sequence. Similarly, in all 4 MLS, the breaks in intron 1 of CHOP were near an Alu sequence. No Alu or other repetitive sequences were found 250 bp upstream or downstream from the break in the ERG intron involved in the AML case. In the AML, the MLS with ESW/CHOP and in one MLS with FUS/CHOP there were one, two and six, respectively, nucleotide identity between the contributing germline sequences in the breakpoint. In the other two MLS cases, two and three extra nucleotides of unknown origin were inserted between the FUS and CHOP sequences. At the junction and/or in its close vicinity, identical oligomers, frequently containing a trinucleotide TGG, were found in both partner genes. Our data thus show that all four genes-FUS, EWS, CHOP and ERG-contain characteristic motifs in the breakpoint regions which may serve as specific recognition sites for DNA-binding proteins and have functional importance in the recombination events taking place between the chromosomes. Different sequence motifs may, however, play a role in each individual case.

Acute Disease↗
PubMed1997

Extracorporeal whole-blood immunoadsorption enhances radioimmunotargeting of iodine-125-labeled BR96-biotin monoclonal antibody.

UNLABELLED: This study investigates the efficacy of tumor radioimmunotargeting with 125I-labeled BR96-biotin monoclonal antibody using a new method, whole-blood immunoadsorption (WBIA), based on direct adsorption of unbound monoclonal antibody (MAb) from blood without preceding separation of plasma. METHODS: Highly tumor-reactive, internalizing, chimeric BR96 MAb of isotype IgG1 binds to a tumor-associated Lewis-type (Le(Y)) cell surface antigen. Forty-six Brown Norwegian male rats were inoculated intramuscularly and beneath the liver or kidney capsule with syngeneic rat colon carcinoma BN7005, expressing Lewis-type antigen, and investigated. The rats were injected intravenously with 3.5-4.5 MBq 125I-labeled BR96-biotin. Twenty of the rats underwent WBIA starting 5 or 12 hr after injection. About six blood volumes were passed through an avidin-gel adsorption column during 2 hr. RESULTS: By using WBIA, whole-body radioactivity was reduced by 50%, and plasma activity by 85%. Both directly after completion of WBIA and 33 hr later, the activity uptake in tumors manifested only a nonsignificant decrease as compared with corresponding controls (p > 0.05) and had approximately similar time-activity curves. Uptake ratios for tumor (T):bone marrow, T:liver, T:kidney and T:lung were enhanced 2.3- to 3.5-fold in all three tumor models, as compared with controls. The ratio of liver tumor to bone marrow was improved from 10:1 to 30:1. CONCLUSION: This new method of WBIA yields significantly improved radioimmunotargeting of highly tumor-reactive, internalizing MAb BR96.

Animals↗
PubMed1996

Extracorporeal immunoadsorption from whole blood based on the avidin-biotin concept. Evaluation of a new method.

This study of 36 rats with rat colon adenocarcinoma transplants was carried out to investigate the efficacy of a new method of whole blood immunoadsorption (WBIA) in removing biotinylated monoclonal antibodies (MAbs) directly from unseparated blood, in order to increase 'the tumor/normal-tissue uptake ratio', as compared with extracorporeal immunoadsorption (ECIA) of antibodies from plasma. Compared with the ECIA system, the overall volume of the WBIA system (comprising only a pump, an adsorption column, a drop-chamber and tubings) was less (3.6 vs. 6.2 ml), and procedure duration 2 h less. The 17 rats undergoing the WBIA procedure, started 12 h after i.v. injection of 4.0-4.5 MBq 125I-BR96-biotin, manifested neither hemolysis nor any other complication; no signs of organ edema were found at dissection; whole body and blood radioactivity values were reduced by 51% and 89.5%, respectively. The WBIA method was as effective as ECIA, but technically simpler, safer and more reliable.

Adenocarcinoma↗
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

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↗
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↗
PubMed1993

Contact allergy to Duraphat.

Skin-sensitizing rosin is present in Duraphat, a fluoride varnish used all over the world. Two cases of hypersensitivity to Duraphat are presented: a dental nurse with dermatitis of the hand and a patient with allergic contact stomatitis.

Dermatitis, Allergic Contact↗