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Biomedical subjects

T Fischer

Publications and source records attributed to T Fischer.

At least 253 records · Page 14Linked to original sources
PubMed1984

Contact sensitivity to nickel in white gold.

Nickel release from white gold discs stored at room temperature for 1 week in synthetic sweat was analyzed. The nickel content of the discs was 2-15%. The nickel release from the discs was 0.09-0.82 microgram. Rhodium plating reduced the nickel release to 0.04-0.54 microgram. 18 nickel-sensitive women were patch tested with the white gold discs and all showed at least 1 positive patch test reaction. All the white gold discs gave a negative dimethylglyoxime test.

Dermatitis, Contact↗
PubMed1984

Nickel release from ear piercing kits and earrings.

Ear piercing with nickel-alloyed studs/clasps involves considerable risk of nickel sensitisation. Stainless steel studs/clasps for ear piercing and different types of earring were stored in synthetic sweat for 1 week. The nickel release was determined. One "hypoallergenic" stud/clasp released 0.005 microgram Ni; 21 unused studs/clasps and earrings released 0.05-3 microgram Ni, and 11 unused studs/clasps and earrings released 6-25 micrograms Ni. 6 earrings which caused dermatitis released 14-442 micrograms Ni. Thus, all studs/clasps and earrings released nickel. Neither gold nor silver plating prevented the nickel release. Nickel-sensitive women were asked to wear studs/clasps releasing various amounts of nickel. The most sensitive of them showed eczematous reactions to studs/clasps releasing nickel down to 0.05 micrograms. The dimethylglyoxime test was positive only when more than 10 micrograms Ni was released.

Alloys↗
PubMed1984

Finn chamber patch test technique.

Proper technique aids reliable patch test results. The Finn chamber volume was determined to be 25 microliters. These studies suggest the optimal volume semi-solid test substance to be 12-15 microliters. More than 18-21 microliters caused significant extrusion of test substance and improper adhesive adherence. Finn chamber paper discs used with solutions absorb a maximum of 17.5 microliters test solutions and keep 15 microliters within the chamber. The evaporation rate of aqueous test solutions from Finn chambers was 1 mg/3 min; thus, the chambers should be applied quickly to avoid drying.

Dermatitis, Contact↗
PubMed1984

Patch test allergens in petrolatum: a reappraisal.

Patch test materials in petrolatum, from 3 different manufacturers and 14 different types were evaluated by gross and microscopic examination. The allergens were noted to be suspended as particles or droplets in the vehicle. Obvious variations in both size and structure of the included allergen were found with the same chemicals but of different manufacture. Several materials do not meet the pharmaceutical standards which should be requested regarding stability, particle size and packing. A more detailed declaration is proposed.

Allergens↗
PubMed1984

Amount of nickel applied with a standard patch test.

The concentration of nickel sulphate was determined in 9-16 mg test samples from commercially available patch test antigens. With two different manufacturers of 2.5% nickel sulphate in pet, the concentration range of 25 samples was 0.7 and 1.1% (+/- 2 SD) respectively, and with one manufacturer of 5.0% nickel sulphate in pet, the range was +/- 0.5%. In a normal patch test, the volume of patch test material applied with the Finn chamber technique should be 12-18 microliter (9-16 mg), but has been found to range between 9 and 50 microliter. Thus the amount of nickel applied in standard patch tests varies within at least 6-fold limits.

Dermatitis, Contact↗
PubMed1984

HLA -A, -B, -C and -DR antigens in individuals with sensitivity to cobalt.

In a skin investigation of 853 individuals working with hard metal manufacturing 39 cases of cobalt allergy were found. Thirty-five of the individuals with cobalt sensitivity and 102 matched controls were HLA-A, -B, -C and -DR typed. No significantly deviating HLA antigen frequencies were observed when the two groups were compared. Thus, there are no signs that a certain HLA antigen would dispose to cobalt allergy. In the cobalt sensitive group the B7 positive individuals showed particularly often simultaneous reactions to other contact allergens (p = less than 0.025). The B12 positive individuals had low reactivity (p = less than 0.0001) while the A28 positive showed high reactivity (p = less than 0.015).

Cobalt↗
PubMed1984

[10 years' integrated medical and occupational rehabilitation in 2d phase facilities--confirmed model or end of a trial?].

Founding of a working group of the rehabilitation facilities of the II. phase has occasioned the present study of developments in this area, as seen in particular from the vocational angle. The main emphasis is the role played by the call for integration in rehabilitation, i.e. inclusion of the disease- or disability-generated occupational problems as a vital social aspect to be considered in the treatment and rehabilitation process. For patients in residential programmes, examples are given from the sector of "occupational therapy and job family-related vocational assessment": preparatory vocational programmes, occupational analysis, vocational assessment, and individualized conditioning. Beyond medical care, the centres of the II. phase had been intended to provide "vocational adjustment services"; critical appraisal however reveals the degree of legal imprecision of this term, as well as its lacking in factual delimitation from other forms of rehabilitative measures stipulated in rehabilitation legislation. Also, the vocational functions assigned to the II. and III. phase respectively, tend to overlap more and more, at least at the conceptual level. What is therefore needed to further development of the vocational tasks and functions to be integrated in the II. phase into a direction where a need does exist and where the specific potential of these centres can be used in a meaningful and economical way: the care of most severely disabled persons for whom vocational services require a special educational emphasis.

Disability Evaluation↗
PubMed1984

Phenotypic characterization in situ of inflammatory cells in allergic and irritant contact dermatitis in man.

The cellular response in allergic and irritant contact dermatitis was analysed in situ with an immunohistochemical double staining technique. Allergic patch test reactions were elicited in 10 patients and irritant reactions in eight cases, using the Finn chamber technique. Skin biopsies were obtained 6-72 h after test applications. Frozen sections of 43 biopsies were investigated by simultaneous staining with rabbit anti-HLA-DR antibodies and various mouse monoclonal antibodies. The cell infiltrates were usually larger in the allergic than in the irritant reactions. However, the kinetics of the cell responses, the phenotypes of the inflammatory cells, their distribution and spatial relationships were similar. It thus appears that the applications of allergens or irritants to the skin generates a cell pattern that to a large extent reflects an immunological readiness for further immune reactions.

Adult↗
PubMed1984

Biology of red cells: non-nucleated erythrocytes as fluid drop-like cell fragments.

Red blood cells as transport cells for oxygen can only be understood by appreciating their specialist functions. In addition to the specific functions of intracellular haemoglobin concentration, their flow behaviour as non-nucleated cell fragments is central to their role in taking up, transporting and releasing reversibly bound oxygen. The unique biology of mammalian red blood cells stems from the fact that they behave akin to fluid droplets. The specific details of their motion in shear fields have been demonstrated in a scientific film: 'Blood fluidity as a consequence of erythrocyte fluidity', film No. C 1494, available through the Institute for the Scientific Film, Nonnenstieg 72, 3400 Göttingen, FRG. The present review presents theoretical details of the flow and deformation of fluids, of suspensions of particles, and of emulsions of fluid droplets immersed in another immiscible fluid. Cytological causes, microrheological details of continuous red cell deformation by deformation orientation, membrane tanktreading, and cytoplasmic eddy flow are described. In addition, the consequences of the fluid drop-like behaviour of the red cells during blood flow in vivo and in vitro are given; an appendix contains an outline of the mechanics of the red cell membrane as a two dimensional elastoviscous fluid film with suspended proteins.

Blood Viscosity↗
PubMed1984

Long-term safety of trioxsalen bath PUVA treatment: an 8-year follow-up of 149 psoriasis patients.

A thorough clinical follow-up study with regard to the occurrence of degenerative skin changes and cutaneous carcinomas was undertaken in 1982 in 149 patients with moderate to severe psoriasis treated with PUVA baths (trioxsalen + UVA). The PUVA treatment had been commenced between 1974 and 1978. With trioxsalen baths a high sensitivity to UVA is obtained. The initial UVA dosage is therefore as low as 0.04-0.08 J/cm2 and in the majority of the patients the maximum daily dose was about 1.0 J/cm2. The accumulated UVA dosage was low. Thus 89% of the patients had received less than 50 J/cm2 in 5-8 years of bath PUVA treatment. No degenerative skin changes were found on PUVA-exposed skin that were not also seen on the facial skin not exposed to PUVA. Two patients showed mild mottling of exposed skin. Otherwise no PUVA-related degenerative changes were observed. No carcinomas were found on bath PUVA-treated skin.

Adult↗
PubMed1984

Conversion factors for ultraviolet radiation dosage with different types of ultraviolet therapy.

Erythema thresholds were determined using 4 different UV units before and after photosensitization with psoralens or coal tar in healthy volunteers. Conversion factors for equivalent erythema-producing UV doses with the different types of treatment were calculated on the basis of the erythema thresholds. A simple mode of transfer of patients between the different treatments with good precision of UV dosage is thus offered.

Coal Tar↗
PubMed1983

Identification of amino acid and nucleotide sequence of the foot-and-mouth disease virus RNA polymerase.

Foot-and-mouth disease virus (FMDV) RNA polymerase was purified from the polyethylene glycol (PEG)-treated supernatant of infected cell media by a combination of ion-exchange chromatography, membrane molecular filtration, and affinity chromatography. The purified RNA polymerase which migrated as a single band of 56,000 molecular weight on a polyacrylamide gel was subjected to automated Edman degradation and the sequence of the first 30 amino acid residues established. On the basis of previous evidence, which indicated that the RNA polymerase was the most 3'-translated polypeptide, plasmids containing cDNA mapping at the 3' end of the genome were characterized by restriction enzyme analysis and nucleotide sequencing. These investigations definitively established the derived amino acid sequence by confirmation of 28 of the amino terminal residues determined by amino acid sequence analysis; the location of the FMDV RNA polymerase coding region at the extreme 3' end of the genome, 96 nucleotides from the poly(A) tail; and the N-terminal cleavage point of the RNA polymerase from its precursor P100 was found to be a glutamic acid-glycine bond.

Amino Acid Sequence↗
PubMed1983

[Concentrations of pollutants in the smoke blowing area of smokers].

The concentrations of particles and nitrogen oxide have been measured in the "blowing cloud" of a smoker. At a distance of 1 m from the smoker, the peak values range from 41 to 750 ppb NO and 3,330 to 99,680 micrograms/m3 particles. These high concentrations decrease very rapidly (half-life period between 2 and 20 s). At a distance of 3 m, there is no more real "blowing cloud". In addition to the sidestream smoke, the relatively high concentrations of particles in the "blowing cloud" of the smoker could also be responsible for the acute irritating effects of the passive smoker.

Humans↗
PubMed1983

Cobalt allergy in hard metal workers.

Hard metal contains about 10% cobalt. 853 hard metal workers were examined and patch tested with substances from their environment. Initial patch tests with 1% cobalt chloride showed 62 positive reactions. By means of secondary serial dilution tests, allergic reactions to cobalt were reproduced in 9 men and 30 women. Weak reactions could not normally be reproduced. A history of hand eczema was found in 36 of the 39 individuals with reproducible positive test reactions to cobalt, while 21 of 23 with a positive initial patch test but negative serial dilution test had never had any skin problems. Hand etching and hand grinding, mainly female activities and traumatic to the hands, were found to involve the greatest risk of cobalt sensitization. 24 individuals had an isolated cobalt allergy. They had probably been sensitized by hard metal work, while the individuals, all women, who had simultaneous nickel allergy had probably been sensitized to nickel before their employment and then became sensitized to cobalt by hard metal work. A traumatic occupation, which causes irritant contact dermatitis and/or a previous contact allergy or atopy is probably a prerequisite for the development of cobalt allergy.

Cobalt↗
PubMed1983

Skin protection against ionized cobalt and sodium lauryl sulphate with barrier creams.

853 individuals who are still working or had previously worked in hard metal manufacture were examined and selected for patch tests with materials from their working environment including metal allergens. The majority of the individuals with positive test reactions to cobalt chloride were retested with serial dilutions of cobalt chloride and with the same serial dilutions after preparation of the skin with a layer of barrier or emollient cream used for hand care in this factory. The irritant effect of sodium lauryl sulphate (SLS) was similarly investigated. The barrier and emollient creams did not give any protection against cobalt chloride or sodium lauryl sulphate. In fact they seemed to enhance the penetration of cobalt ions. Their use in protection against metal allergens and cutting fluids is questionable.

Cobalt↗
PubMed1983

Relationship between nickel and cobalt sensitization in hard metal workers.

853 hard metal workers were examined and patch tested with 20 substances from their environment, including nickel and cobalt. Nickel sensitivity was found in 2 men and 38 women. 88% of the nickel-sensitive individuals had developed a jewelry dermatitis prior to employment in the hard metal industry or before the appearance of hand eczema. 29% of the hard metal workers gave a history of slight irritant dermatitis. In the nickel sensitized group, 40% had had severe hand eczema which generally appeared 6-12 months after starting employment. In 25% of the cases, nickel sensitive individuals developed cobalt allergy, compared with 5% in the total population investigated. Most facts indicate that nickel sensitivity and irritant hand eczema precede cobalt sensitization. Hard metal workers with simultaneous nickel and cobalt sensitivity had a more severe hand eczema than those with isolated cobalt or nickel sensitivity or only irritant dermatitis. 64% of the female population had pierced ear lobes. Among the nickel allergic women, 95% had pierced ear lobes. The use of earrings containing nickel after piercing is strongly suspected of being the major cause of nickel sensitivity. Piercing at an early age seems to increase the risk of incurring nickel sensitivity.

Adult↗