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Biomedical subjects

T Fischer

Publications and source records attributed to T Fischer.

At least 235 records · Page 13Linked to original sources

Comparative multi-center study with TRUE Test and Finn Chamber Patch Test methods in eight Swedish hospitals.

292 individuals were patch tested with twelve allergens, using a new patch test technique, TRUE Test (TT). As controls, the same allergens in standard concentrations in petrolatum were applied using the Finn Chamber technique (FC). The allergen doses used in TT were chosen according to results from a previous serial dilution patch test study. There were reactors to all twelve allergens. The concordance of positive reactions between TT and FC was 78%. 10% were indicated only with TT and 12% FC only. Irritant reactions occurred in the same order of magnitude for the two tests. Weak positive, uncertain, and irritant reactions observed with the different test methods used, indicate minor errors of allergen dosage in both. The investigation indicates that the TRUE Test method is simple to handle, is well standardized and gives good accuracy with the 12 allergens investigated.

Allergens↗

Granular cell tumors: evidence for heterogeneous tumor cell differentiation. An immunocytochemical study.

Eighteen granular cell tumors from various sites were examined with antisera directed against protein S-100, neuron specific enolase (NSE), alpha-1-antichymotrypsin, and alpha-1-antitrypsin, glial fibrillary acidic protein (GFAP), lysozyme, factor VIII-related antigen, myoglobin and vimentin, as well as with a monoclonal antibody (lu-5) directed against a panepithelial marker. The immunocytochemical reaction pattern of the tumors was heterogeneous. The brain and pituitary tumors and one thyroid tumor reacted for alpha-1-antichymotrypsin and alpha-1-antitrypsin, but not for S-100 protein and NSE. However, tumors from other sites showed immunoreactions for S-100 protein and NSE and some also for vimentin. Reactions for alpha-1-antichymotrypsin and alpha-1-antitrypsin were not observed. All other reactions were similarly negative. We conclude that the morphologically homogeneous group of granular cell tumors is biologically heterogeneous.

Cell Differentiation↗

[Neuropathologic findings in 13 deceased patients with acquired immunologic deficiency syndrome].

The neuropathological findings in 13 patients with the acquired immune deficiency syndrome (AIDS) and with AIDS related complex (ARC) are reported. Six patients presented with neurological symptoms, whereas autopsy revealed CNS involvement in nine cases. Four patients showed neither neurological nor neuropathological abnormalities. The most frequent neuropathological diagnoses were toxoplasma encephalitis (4 cases) and multiple or solitary cerebral necroses (3 cases). Long tract degeneration of the spinal cord was found in 2 cases. Cytomegalovirus infection, progressive multifocal leukoencephalopathy, primary lymphoma of the CNS, infiltration of the leptomeninges by plasmocytoma cells and a solitary metastasis of a bronchial carcinoma were diagnosed in one case each. Subacute leukoencephalitis, mentioned frequently in the literature, was not present in this material. In one case, however, status spongiosus and gliosis was found in the cortex and basal ganglia. As similar spongy changes can be seen in mice infected experimentally with retroviruses, a pathogenetic role of the human T-cell lymphotropic/leukaemia virus type III (HTLV-III) cannot be ruled out. Astrogliosis and hypertrophy of astrocytes were found in nine cases. Morphometrically, the number of astrocytes was significantly higher in AIDS patients than in control cases which were selected randomly on grounds of comparable age. Whether this finding bears some relationship with HTLV-III encephalopathy remains open to further investigation. Glial nodules were found in four cases; according to silver impregnation they were composed of microglial elements.

Acquired Immunodeficiency Syndrome↗

Use of a minicondylar plate for metacarpal and phalangeal periarticular injuries.

The minicondylar plate fixation system is a new method for stable internal metaphyseal bone fixation about the metacarpophalangeal (MP) and proximal interphalangeal (PIP) joints. Indications for its use are rigid stabilization of fracture, osteotomy, and the bony components of composite tissue transfer. The device should be used in deference to other techniques when early active range of motion is pursued. Its best use is in the face of combined injury or osteotomy with tenolyses/capsulotomy. This implant permits stabilization of small epiphyseal fragments with minimal interference of joint function and perhaps a reduction of irritation of the extensor aponeurosis. Disadvantages include the need for careful preoperative planning because of this implant's small size and unforgiving tolerances of application. The data is included for the first 65 consecutive cases of its use. Despite the institution of range of motion therapy within five days in 77% of the cases, there were no nonunions. Two cases of delayed union were successfully treated by addition of cancellous bone grafts without revision of the fixation devices. Problems included malignments (three cases), infections (two cases), and soft tissue coverage (four cases). Aseptic necrosis of bone is associated with metacarpal head fractures and is seen with the use of this implant in treating such intraarticular fractures.

Bone Plates↗

Products of two common alleles at the locus for human placental alkaline phosphatase differ by seven amino acids.

Amino-terminal amino acid sequences (42 residues) were determined for the products of the three common alleles at the human placental alkaline phosphatase [orthophosphoric-monoester phosphohydrolase (alkaline optimum), EC 3.1.3.1] gene locus. The sequences differ at position 3, which is proline in types 1 and 2 but is leucine in type 3. cDNA libraries were constructed in phage lambda gt11 and used to isolate clones covering the coding regions of types 1 and 3 cDNAs. Comparison of the deduced amino acid sequences of the types 1 and 3 proteins showed 7 differences out of 513 amino acids, each due to a single base substitution. cDNA sequence comparisons showed three silent substitutions in the coding regions and three base differences in the greater than 1 kilobase pairs of 3' untranslated sequences.

Alkaline Phosphatase↗

Phenotypic difference between allergic and irritant patch test reactions in man.

Cellular responses in allergic and irritant contact dermatitis were analysed in situ using an immunohistochemical double staining technique with the aim of uncovering phenotypical differences of diagnostic importance. Allergic and irritant patch test reactions were elicited in 9 individuals using the Finn chamber technique. Thirty-nine skin biopsies from these reactions and from petrolatum controls were obtained 4 to 20 days after the test applications. Cell infiltrates were present throughout the observation period in both allergic and irritant reactions, but were usually greater in the former. In both types of reaction, anti-Leu 3a reactive cells predominated over anti-Leu 2a reactive cells. HLA-DR expression on keratinocytes was found in 9 of 14 allergic reactions, but not in irritant reactions or control areas. HLA-DQ antigens were not detected on keratinocytes. The presence of HLA-DR antigens on keratinocytes may reflect an immunological response of the allergic reactions, and thus be of diagnostic relevance.

Adult↗

Systemic responses to tourniquet release in children.

The hemodynamic and metabolic effects of deflation of pneumatic tourniquets were assessed in 15 children, seven of whom had bilateral tourniquets applied. Systemic acidosis from release of lactate and PaCO2 after tourniquet deflation did not cause adverse effects in these healthy children. Larger increases in lactate were seen with longer tourniquet inflation times (greater than 75 min) or with bilateral tourniquets. The greatest decrease in pH was seen with simultaneous deflation of bilateral tourniquets. Heart rate did not change with tourniquet deflation, whereas systolic blood pressure decreased 8-10 mm Hg with deflation. Blood pressure returned to control values within 5-10 min; no arrhythmias were seen. Recommendations to minimize the systemic metabolic effects after release of tourniquets in children under general anesthesia include the following: 1) attempt to limit tourniquet inflation times to less than 75 min; 2) use controlled ventilation prior to and after tourniquet deflation to remove the respiratory component of acidosis; 3) check blood gas tensions within 5 min of tourniquet deflation in children with long tourniquet inflation times (greater than 75 min), and where bilateral tourniquets are deflated simultaneously or within 30 min of each other.

Adolescent↗

Hand eczema among hard-metal workers.

Seven hundred seventy-six of 800 workers in a hard-metal factory were investigated. The prevalence of hand eczema and irritant reactions of the hands was 10% and 15% respectively. Of 1,006 workers who had left the industry during the previous ten years, 87 had had hand eczema. The cumulative incidence of hand eczema for these ten years was estimated to be 17%. Fifty-two percent of the hand eczemas and 67% of the irritant reactions started during the first year of work. The majority of both the hand eczemas and the irritant reactions first appeared in grinding activities. Wet grinding and oil grinding entailed the highest risks of hand eczema. Hand eczema was significantly more common in individuals with an atopic background. Eighteen percent of the individuals with present or previous hand eczema had positive patch-test reactions. Positive patch tests were equally common among individuals with irritant reactions and those with normal skin.

Dermatitis, Contact↗

The Finn chamber methylene blue ring.

Metallic aluminium and methylene blue applied to human skin interact and give a strong resistant coloration, obtained neither with methylene blue itself nor with other dyes. The reaction proves that aluminium is not an inert material and that the aluminium in Finn chambers can be expected to interact with other patch test substances.

Aluminum↗

False-positive, follicular and irritant patch test reactions to metal salts.

853 hard metal workers were patch tested with nickel sulphate 5%, potassium dichromate 0.5% and cobalt chloride 1%, each in petrolatum. Non-allergic reactions appeared in 6.5% of the nickel tests, 13% of the chromium tests and 18.3% of the cobalt tests. Most of the individuals with positive, poral or pustular reactions were retested with serial dilutions of metal salts in pet. and in water. The accuracy of a positive initial nickel reaction was 83%, a chromium reaction 40% and a cobalt reaction 62%. The nonallergic reactions were partly reproducible and correlated with both the type of patch test material and with individual factors. Weak and moderately strong positive patch test reactions to metal salts may be irritant and should be checked with serial dilution tests or at least be retested. A reduction of the cobalt chloride concentration from 1% to 0.5% in the standard test material is discussed.

Chromates↗

Aluminium in Finn chambers reacts with cobalt and nickel salts in patch test materials.

Aluminium has a greater affinity for electrons than cobalt and nickel. Therefore, cobalt and nickel ions would be expected to exchange with metallic aluminium in Finn chambers. This theory has been proven to be valid, as shown in 2 series of experiments: first, cobalt and nickel salt solutions (0.25 M) etch a metallic aluminium surface; secondly, aluminium Finn chambers kept in 10(-3) M nickel salt solutions significantly reduce the concentration of dissolved nickel. Dichromate solutions do not etch an aluminium metal surface significantly. Petrolatum, which is routinely used as vehicle in standard patch tests, probably protects the aluminium of Finn chambers from the interaction of cobalt and nickel salts. The interaction may have significance in tests with solutions.

Aluminum↗

Nucleotide and amino acid sequence coding for polypeptides of foot-and-mouth disease virus type A12.

The coding region for the structural and nonstructural polypeptides of the type A12 foot-and-mouth disease virus genome has been identified by nucleotide sequencing of cloned DNA derived from the viral RNA. In addition, 704 nucleotides in the 5' untranslated region between the polycytidylic acid tract and the probable initiation codon of the first translated gene, P16-L, have been sequenced. This region has several potential initiation codons, one of which appears to be a low-frequency alternate initiation site. The coding region encompasses 6,912 nucleotides and ends in a single termination codon, UAA, located 96 nucleotides upstream from a 3'-terminal polyadenylic acid tract. Microsequencing of radiolabeled in vivo and in vitro translation products identified the genome position of the major foot-and-mouth disease virus proteins and the cleavage sites recognized by the putative viral protease and an additional protease(s), probably of cellular origin, to generate primary and functional foot-and-mouth disease virus polypeptides.

Amino Acid Sequence↗

UV treatment of uraemic pruritus reduces the vitamin A content of the skin.

The effect of phototherapy on uraemic pruritus and vitamin A content in serum and epidermis was investigated in ten patients with chronic renal failure. The patients and five healthy controls were given repeated whole-body irradiation of UV-A + UV-B (total dose 7.9 + 1.3 J cm-2). Serum and skin samples were obtained before and after the treatment. Serum samples were analysed for retinol, retinol-binding protein and carotene and epidermis samples for retinol, 3-dehydroretinol and carotene. Before treatment, the retinol concentrations in serum and epidermis were higher in patients than in controls. The treatment, which relieved seven patients of pruritus, reduced the epidermal retinol from 11.6 +/- 4.5 to 7.0 +/- 3.8 nmol g-1 protein (P less than 0.02). A similar reduction occurred in the controls (4.5 +/- 1.0 v. 1.7 +/- 1.0, P less than 0.01). No changes of epidermal 3-dehydroretinol, carotene or the serum parameters occurred in either patients or controls. The putative relationship between uraemic pruritus and hypervitaminosis A and the response of this condition to UV therapy is discussed.

Adult↗