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Biomedical subjects

F Streiff

Publications and source records attributed to F Streiff.

At least 91 records · Page 5Linked to original sources

Comparison of in vitro effects of normal IgG and of a monoclonal IgG on the rheological behaviour of erythrocytes.

Erythrocyte sedimentation, viscosity, electrophroetic mobility, and osmotic fragility were measured in a study of the rheological behaviour of the erythrocyte in vitro. In comparison with physiological saline solution, a suspending medium containing a gamma2lambda2 monoclonal IgG from a patient with multiple myeloma caused rheological changes 2-3 times as great as a medium with normal IgG. Our results demonstrate the existence of nonimmunological interactions between erythrocytes and normal or monoclonal immunoglobulins, and they raise questions about the widely held assumption that paraproteins are structurally 'normal'.

Blood Viscosity↗

[Monoclonal immunoglobulins and serum viscosity: contribution of the idea of activation energy to the paraprotein concept (author's transl)].

The simultaneous study of dynamic and cinematic viscosity in 34 control sera and 49 paraprotein sera showed that there was a simple relationship between the viscosity and the total serum protein content both in normal sera and in paraprotein sera. When the ratio of monoclonal immunoglobulins/total proteins is less than 55%, the viscosity is little or not modified in the case of the IgGk paraproteins studied, whereas it was increased in the case of IgA, IgM and IgG LAMBDA SERA. Beyond 2 cSt, it is not however possible to incriminate a particular type of heavy chain nor even a light chain. The measurement of the viscosity in relation to the temperature permitted us to show that the IgA, IgG, and IgM sera studied all presented an activation energy of outflow (E in Kcal) higher than that of normal sera and the highest rise is due to IgA paraproteins. The concept of energy activation permits us to say that paraproteins have a different behaviour from normal proteins, probably due to disorders in their structural arrangement.

Blood Viscosity↗

Characterization of the human peripheral effector cells mediating antibody dependent cellular cytotoxicity against allogenic cells.

The effector cell populations in human peripheral blood responsible for antibody-dependent cellular cytotoxicity against allogenic cells coated with HLA polyspecific antibodies were investigated using several separation techniques including preparative electrophoresis. Electrophoresis produced a marked effector cells enrichment in a range of 2--5 fractions which exhibited an intermediary electrophoretic mobility. Monocytic cells do not contribute an effector mechanism but minor subsets of polymorphonuclear cells and nylon wool non-adherent non-phagocytic lymphocytes displayed ADCC. Both effector cell populations were found to exhibit a similar electrical charge of cell surface centered around -1.05 micrometer . sec-1 V-1 cm. These observations provided a precise biophysical basis for the identification of effector cells in ADCC.

Adult↗

[In vitro influence of albumin, gammaglobulin and fibrinogen on the sedimentation rate and the rheological behaviour of the red cell (author's transl)].

The complexity of the mechanisms which enter into play in the phenomenon of erythrocyte sedimentation have for long aroused the curiosity of research workers. A simultaneous study of this parameter and of the viscosity, of the relative zeta potential together with the osmotic fragility, led us to appreciate the respective actions of three isolated plasma proteins : albumin, immunoglobuin G, fibrinogen, on the ESR and on the rheological properties of the red cell.

Albumins↗

Type IIa hyperlipoproteinemia and the HLA system.

The comparative study of a control group made up of 340 healthy subjects, a group of 100 unrelated patients, all showing signs of type II hyperlipoproteinemia and a family of 15 members covering three successive generations, brings to light the highly significant increase of the recurrence of HLA Bw17 antigen and the increase in frequency of HLA Bw35 antigen.

Gene Frequency↗

[HLA DRw in ankylosing spondylitis].

The association of ankylosing spondylarthritis with the B locus and more specifically with the B 27 antigen, is the closet known for any illness. The absence of linkage with the DRw antigens studied during this project, in 50 patients, can give rise to the hypothesis that spondylarthritis is associated with determinants situated on the B lymphocytes, linked to the HLA-B locus.

Adult↗

HLA antigens and hereditary hemorrhagic telangiectasia.

HLA antigens (27 HLA alleles of the A and B loci) were determined in 20 subjects of the same family, covering three generations; 6 of them were suffering from hereditary hemorrhagic telangiectasia. The haplotype HLA A2, Bw17 was found in all the sufferers. The same haplotype was not found in clinically health members except two of the generation III, but a visceral angiomatosis without clinical evidence cannot be excluded. An association of hereditary hemorrhagic telangiectasia with the haplotype HLA A2, Bw17 can be suspected in this family.

Female↗

Hereditary diffuse articular chondrocalcinosis. Dominant manifestation without close linkage with the HLA system in a large pedigree.

Thirty-nine members of one family, covering three generations, were HLA-typed. Twenty-five suffered from primary diffuse articular chondrocalcinosis, and all had the same dominantly transmitted autosomally controlled disease. This was characterized by acute articular attacks, which always started before the age of 35, and radiologically by typical cartilaginous and fibrocartilaginous deposits associated with para-articular calcifications. The lesions were both peripherally and axially generalized. None of the 28 HLA antigens tested seemed related to the disease, nor did the disease segregate with an HLA haplotype.

Adult↗

HLA antigens and alkaptonuria.

Thirty members of Family C, which included cases of alkaptonuria and ochronosis, were investigated by means of HLA typing and homogentistic acid determination. The antigen HLA B27 was found in one of the two members of the first generation, in all eight members of the second generation, and in 15 of the 21 members of the third generation. Eight of 10 subjects suffering from alkaptonuria, with or without ochronotic arthropathy or spondylosis, had B27. The gene for B27 is not the gene determining homogentisic acid oxydase synthesis but this study suggests that it may be associated or linked to it.

Alkaptonuria↗

[HLA-B27 antigen and alkaptonuria].

Study of urinary homogentisic acid and a determinantion of group HLA were carried out for 36 members of a family spread over three generations with three cases of ochronotic rheumatism in the second generation. Alkaptonuria was discovered in seven other subjects, six of them members of the third generation: urinary elimination was poor, less than 0.60 g/24 hours. There is a certain degree of consanguinity in the family studied here and these findings do not therefore rule out a recessive autosomal transmission of the alkaptonuria. They do however lead to the consideration that alkaptonuria may sometimes be found in heterozygotic subjects. A genetic relationship between HLA complex and alkaptonuria can only be claimed with difficulty from this familial study, but the high frequency of B 27 antigen (29 out of 36 members carring it) leaves room for the hypothesis that the B 27 gene, or more precisely a gene associated with the B 27 gene, plays a part in the development of ochronotic rheumatism.

Adult↗

[Evaluation of a method of study of platelet aggregates using formol fixation].

A new approach for testing platelet aggregates by formol fixation (Wu and Hoak) is presented. The investigations are made either in vitro by the study of aggregation in the presence of ADP, or in vivo after thrombin ADP perfusion in the rabbit. The calculation of an index of aggregability comparing fixed and non fixed platelets permits an evaluation of the presence of aggregates.

Adenosine Diphosphate↗

[Cytogenetic studies in spontaneous abortions].

During the three last years, the authors carried out cytogenetic studies of couples with spontaneous abortions, and of spontaneously aborted foetuses. Among 99 couples studied, 9 abnormal karyotypes were detected. In two cases, maternal balanced translocation appears obviously responsible. Concerning aborted foetuses on 46 karyotyped specimens, 13 are found to bear chromosome anomalies. The authors consider the value of cytogenetic studies when repeated spontaneous abortions occur.

Abortion, Spontaneous↗