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Biomedical subjects

F Jorgensen

Publications and source records attributed to F Jorgensen.

At least 19 recordsLinked to original sources

Histocompatibility determinants in Israeli Jewish patients with multiple sclerosis.

The distribution of 24 HLA antigens of the A and B loci was investigated in 197 Israeli Jewish patients with multiple sclerosis (MS) from various Jewish ethnic origins including central and eastern Europe, countries bordering the Mediterranean, the Middle East and from native-born Israelis. The results were compared with the HLA antigen frequencies in a control sample of 455 unrelated individuals representing the general Jewish population. The frequency of HLA-Bw40 among all MS patients (15%) was significantly greater (P less than 0.001) than among the controls (7%). In contrast to the findings in MS patients from other populations, there was no increased frequency of A3 and B7 and Dw2 was present in only one out of 28 patients. The study showed a similar distribution of HLA-A and -B locus antigens, especially of Bw40, in Jews of diverse ethnic origins represented in the control group.

Epitopes

Osteosynthesis of medial fractures of the femoral neck by sliding nail-plate fixation.

Sliding-nail-plate osteosynthesis of displaced medial fractures of the femoral neck was carried out in 65 consecutive cases. The appliance presented here differs from other sliding-nail plates as it has no fixed angle between the nail and the plate. Immediate postoperative weight-bearing was permitted. The average follow-up period was 2.2 years. Union of the fractures was seen in 74% and avascular necrosis in 21%. Complications were few, which we attribute to the early mobilization of the patients.

Adult

HLA-D typing by homozygous typing cells. A statistical analysis of experimental and biological variation.

Several normalization procedures have been applied to single MLC-typing experiments in order to neutralize experimental variation and hence to secure assignment of HLA-D phenotypes. The present paper concerns a statistical description and isolation of experimental and biological factors in repeated MLC-typing experiments. The statistical model used gives a meaningful description of the variables in MLC as judged by its application to MLC-typing data of HLA-identical siblings. Subsequent testing of the model in an HLA-A, -B,-C and -D-genotyped family material provides evidence that the level of typing response to selected homozygous typing cells may be influenced by factors coded for by the homologous HLA-D region. It is, however, concluded that such evidence must be accepted with caution due to the (for the present statistical purpose) suboptimal design for the HLA-D typing experiments and hence the relative insensitivity of the method. A general method for locating erroneous triplicates is devised.

Analysis of Variance

Cell mediated lympholysis in man: an attempt to type with cytotoxic lymphocytes.

From approximately 3,000 CML combinations, originally established in order to evaluate the qualitative and quantitative influence of the serologically defined HLA-A, B, and C antigens on cellular, complement independent cytolysis, 12 combinations were selected yielding reproducible positive cytolysis on allogenic target cells, although no HLA-antigenic sharing could be demonstrated between stimulator and target lymphocytes. These 12 CytoToxic Lymphocytes (CTL's) have been tested in parallell as "CML typing combinations" against lymphocytes from a random population sample of 100 unrelated Danes. Based on a pairwise analysis 11 of these CTL's could be classified into two groups of significantly correlated CTL's. These two groups do not define monospecific traits of allelic genetic origin as judged by a mutually positive correlation and a poor fit to Hardy-Weinberg equilibrium. The traits defined by these groups may be either partially identical or governed by closely linked loci. The same groups were identified and the same conclusions reached after exclusion of those individuals in the population sample where HLA-A, B, C, or D antigens may be targets for destruction. Thus, this study gives direct evidence that known HLA antigens are not sole target determinants in CML or that cytotoxic lymphocytes recognize HLA molecules in a different way than lymphocytotoxic antibodies. The studies underline the immunogenetic complexity of CML although this reaction is most probably governed by genes in the HLA region. It is suggested that cytotoxic lymphocytes may recognize "backbone structures" of the HLA molecules.

Cytotoxicity Tests, Immunologic

The impact of HLA-A, B or HLA-D identity on the MIF production in MLC.

The relative influence on MIF release in MLC of different parts of the HLA region was studied in 1) MLCs between cells from HLA-A and B identical (probably HLA-D unidentical) unrelated persons and 2) MLCs between cells from HLA-D identical, HLA-A and B unidentical unrelated persons. It was found that the HLA-D part of the region has the major effect on the MIF production. Studies of MIF activity in supernatants from mitomycin treated cultures lent some evidence to the hypothesis that there is an extreme linkage disequilibrium between the HLA-D alleles and hypothetical separate MIF alleles. Examination of families with crossover between the HLA-A, B and HLA-D part of the region is required for confirmation of these findings.

Epitopes

Frequency dependent changes in the amplitude of the cochlear microphonic potential of the pigeon ear during transient anoxia.

The effect of transient anoxia on the cochlear microphonic potential at different sound frequencies was investigated. The microphonic potential was recorded with glass microelectrodes in the ductus cochlearis of the pigeon ear. Transient anoxia had different effects, related to frequency, on the amplitude and the relative phase angle of the microphonic potential recorded from one place in the ductus cochlearis. At frequencies equal to and higher than the best frequency the amplitude of the microphonic potential was more sensitive to anoxia than it was at lower frequencies. Microphonic potential at 1 kHz lower than the best frequency was often enlarged in amplitude during transient anoxia. The results suggest that this frequency-dependent effect is a positional one. Changes in the phase were largest around the best frequency. It is inferred that anoxia causes complex changes in the pattern of vibration in the cochlear partition. The observed changes in amplitude and also changes in phase are caused by the combined effects of reduction of the endolymphatic potential and changes in vibration pattern.

Acoustic Stimulation

Deposits of immunoglobulins and complement in the dermoepidermal junction of patients with anaphylactoid purpura.

Skin biopsies from 3 patients with anaphylactoid purpura examined by an immunofluorescence technique revealed deposits of immunoglobulins, complement C3, and fibrinogen in the dermo-epidermal junction and in vessel walls of clinically involved as well as uninvolved skin. The deposits in the dermo-epidermal junction are similar to those seen in the skin of patients with systemic lupus erythematosus.

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