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Biomedical subjects

C Steffen

Publications and source records attributed to C Steffen.

At least 109 records · Page 6Linked to original sources
PubMed1978

[Investigations on the performance of calcium selective disc-electrodes with electrically charged and neutral ligands in anaerobic serum measurements (author's transl)].

Anaerobically prepared serum samples from healthy subjects were simultaneously analysed for Ca++ in a flow-through-system of three ion selective disc-electrodes (electrochemical multimeasurementsystem). Two of the sensors contained electrically charged ligands, the third contained a neutral carrier. With neutral carriers an improvement of performance was noted in that there was a large increase in selectivity toward H+- and NH+4-ions and a distinct enhancement of reproducibility.

Anaerobiosis↗
PubMed1978

Demonstration of anticollagen antibodies in rheumatoid arthritis synovial fluids by 14C-radioimmunoassay.

Twenty-seven synovial fluids from rheumatoid arthritis (RA) patients and 17 synovial fluids from controls were investigated in a new radioimmunoassay for anticollagen antibodies. In vitro labeled human 14C-collagen of type I in native or denatured state was used as antigen. Passive hemagglutination was used in comparison. Parameters for defining positive results in radioimmunoassay were evaluated on the basis of control synovial fluids. Synovial fluids from 20 RA patients (74%) showed antibodies to denatured collagen; synovial fluids from 8 RA patients (30%) also demonstrated antibodies to native collagen. Control fluids of posttraumatic effusions were negative; among the other controls synovial fluid from 1 psoriatic arthritis patient reacted positively. Inhibition experiments showed that antibodies to denatured collagen cross-reacted with native collagen. Inhibition with human denatured type III collagen displayed strong cross-reactivity of anti-type I collagen antibodies with type III collagen.

Adult↗
PubMed1978

Studies on rosette formation of human lymphocytes with pig red blood cells.

In this paper, data are presented which indicate that receptors of human peripheral blood lymphocytes (PBL) for pig erythrocytes (PRBC) and sheep erythrocytes (SRBC) are identical or at least very similar to each other with a higher avidity of PBL for SRBC than for PRBC. As an average, 50 +/- 9% of human PBL formed PRBC rosettes (Ep), compared to 70 +/- 7% of SRBC rosettes (Es). Lymphocytes incubated with SRBC plus PRBC ('co-rosetting') formed 10 +/- 5% of mixed rosettes (Em) but no pure Ep. Resuspension of rosetted lymphocytes followed by co-rosetting with the other erythrocyte species revealed that the majority of Ep became Em, while the majority of Es remained pure Es even after co-rosetting with PRCB; no pure Ep was newly formed. Incubation at 37 degrees C abolished almost all Ep as compared to 9% Es. Anti-thymocyte serum inhibited both types of rosette formation. PBL from patients with chronic lymphatic leukemia formed only 2.5 +/- 2.5% Ep. 1.7 +/- 1.1% of PBL expressed both membranes immunoglobulins and receptors for PRBC. Trypsin treatment abolished both kinds of rosette formation almost completely, while neuraminidase treatment of erythrocytes led to a raise in Ep formation from a mean of 53% to a mean percentage of 68%. Electron microscopic investigations did not reveal differences between binding sites of lymphocytes for PRCB and those for SRBC; however, with a technique different from the conventional one, intimate contact areas were observed between lymphocytes and both kinds of red blood cells.

Animals↗
PubMed1977

Induction of acute and chronic arthritis by intra-articular injection of preformed collagen-anticollagen complexes.

Three groups of rabbits were injected intra-articularly into the knee joints with preformed complexes of hydroxamated collagen and antiserum to denatured collagen respectively, with hydroxamated collagen and normal serum, hydroxamated collagen, anticollagen serum or saline as controls. From twelve rabbits, receiving only one injection and investigated 8 h later, only the joint tissues of rabbits which received immune complexes showed acute arthritis with severe infiltration of polymorphonuclears, leucocyte thrombi in vessels and haemorrhages. From six rabbits, receiving two consecutive injections (day 0 and day 2) and investigated 12 h after the last injection, only the joint tissue of rabbits which received immune complexes showed subacute-chronic arthritis. From sixteen rabbits receiving four consecutive injections day 0, day 2, day 7 and day 14) and investigated 7 days after the last injection, only the joint tissue of rabbits which received immune complexes showed severe chronic arthritis with infiltration of plasma cells, lymphocytes and nodule-like accumulation of lymphocytes whilst their joint fluid showed additionally a distinctly increased number of polymorphonuclears (3-15 x 10(6)) which differed with P less than 0-01 statistically from all controls.

Acute Disease↗
PubMed1976

[Studies on the immune status of patients with operated and irradiated cervical and breast cancer. III. Comparative investigation of the immune status of patients with breast cancer treated by operation and irradiation and of patients with cervical cancer treated either by operation or irradiation (author's transl)].

The immunological reactivity of 19 operated cases of breast cancer (14 T1 2, 5T3) was investigated before and at 3-weekly intervals up to 12 weeks after radiotherapy by means of a large panel of techniques. The results were compared with two groups of identically-investigated patients, one consisting of 11 cases of cervical cancer (stage III), treated solely by irradiation and the other of 12 cases of cervical cancer (Stages I a and II b), treated by operation only. Before irradiation and in the non-irradiated group cellular immunity appeared to be more disturbed in cases of breast cancer than in cases of cervical carcinoma, as shown by the lowest number of lymphocytes, the lowest number of spontaneously-rosetting lymphocytes, the lowest percentage of DNCB sensitization in patients and the lowest percentage of Tuberculin-positive skin tests. In both types of carcinoma the humoral immunity appeared to be impaired, as apparent from the lowered immune response to tetanus vaccination. Other parameters of humoral immunity such as the immune globulin concentration, iso- and heteroagglutinine, the titre of measles antibodies or membrane fluorescence of lymphocytes showed no dinstinct trends during the investigation period. After irradiation a) inhibiting and b) stimulating influences were observed: a) The incidence and extent of the immune response to tetanus vaccination was further reduced and a distinct lymphopenic effect was observed. b) The incidence of positive skin tests with varidase, as well as the number of spontaneously-rosetting lymphocytes increased after the commencement of irradiation. Apart from the known sensitization with DNCB and skin tests with tuberculin, determination of the antitoxin titre before and after tetanus vaccination provided the most reliable results in regard to immunological reactivity in the investigated tumour patients.

Antibodies, Neoplasm↗
PubMed1976

[Microfluorometric demonstration of thyroglobulin antibodies with the defined antigen substrate spheres (DASS) system].

Previous investigations showed that quantitative immunofluorescence using antigens covalently bound to agarose particles represents a reproducible and sensitive assay for antibodies in experimental antisera. In this paper data are presented which show that also thyroglobulin antibodies in patients sera can be demonstrated using the defined antigen substrate spheres (DASS) system with thyroglobulin as antigen. Sera of 45 patients with various thyroid diseases were investigated for the presence of thyroglobulin antibodies using passive haemagglutination and the quantitative immunofluorescence technique. Comparable results were obtained with both techniques. Advantages and disadvantages of both methods are discussed.

Autoantibodies↗
PubMed1976

Experimental pulpal immunization. I. Route of application and demonstration of immune response.

The experimental exposure of the pulpal room of rabbit teeth made it possible to apply an ovalbumin agar gel deposit into the pulpal room and subsequently investigate the immune response. Diffusion of antigen from the agar into environment was proven. After 3 weekly applications 5 rabbits showed hemagglutinating anti-ovalbumin titers between 1:128 and 1:512, while 7 rabbits receiving 10 weekly applications had titers between 1:8000 and 1:128,000. Control rabbits which received the agar deposit alone showed no antibody response. Control rabbits which obtained 3 identical weekly doses of ovalbumin in PBS by subcutaneous injection showed an identical immune response as animals immunized via the pulpal room. Specificity of antibodies was ascertained by passive hemagglutination with control antigens and hemagglutination inhibition. Intradermal injection of ovalbumin in 3 rabbits which obtained pulpal immunization, induced an Arthus reaction. The precipitating property of ovalbumin antibodies and their identity with defined ovalbumin antisera was proven by gel diffusion. The results obtained show, that antigens present in the pulpal room provide a strong immunogenic stimulus.

Animals↗
PubMed1975

[Irradiated cases of cervical and breast cancer II. Comparative investigation of the immune status of irradiated cases with stage III cancer of the cervix and operated, non-irradiated cases (author's transl)].

Eleven patients with stage-III cancer of the cervix were investigated before, during and after radio-therapy in regard to their state of humoral immunity on the basis of determinations of the serum IgG, IgM and IgA concentration, of hetero- and isoagglutinins, of tetanus antitoxin before and after vaccination with toxoid, of measles antibodies and of the percentage of lymphocyte membrane fluorescence. The cellular immunity of the same patients was investigated by determination of the percentage of spontaneously-rosetting lymphocytes, of skin-test reactivity with DNCB before and after sensitization, of skin-test reactivity with candida, trichophyton, varidase, OT and staphylo antigen. The function of polymorpho-nuclear leucocytes was investigated by means of the NVT test and St. aureus, E. coli and latex particles. All investigations were performed both before, and 3, 6, 9 and 12 weeks after the commencement of radiotherapy and the results were compared with those of an operated, non-irradiated group (stages I b and II a). Two types of noteworthy results were observed: 1. A decrease in immunological reactivity, probably in connection with cancer, since this reaction was observed both in irradiated and in non-irradiated cases, characterized by lowered or absent immune answer to tetanus toxoid, lymphopenia, decrease in sensitization to DNCB and less positive skin tests to old tuberculin and varidase. 2. An additional inhibition (although in one investigation stimulation of the immune answer was also seen), probably in connection with radiotherapy, characterized by an additional decrease in immune answer to tetanus toxoid, in skin sensitivity to DNCB sensitization and in tests with old tuberculin, and an augmented lymphopenia, as well as an increase in positive skin tests with varidase. No significant changes were observed with any other method.

Antibody Formation↗
PubMed1975

[Investigations on the immune status of operated and irradiated cases of cervical and breast cancer I. immune status before and after surgery of cancer of the cervix, stages I b and II a(author's transl)].

12 patients were investigated in regard to their state of humoral immunity by means of the following determinations: IgG, IgM, and IgA concentrations in the serum, hetero- and isoagglutinins, tetanus antitoxin before and after immunization with toxoid measles antibodies and the percentage of lymphocytes with membrane fluorescence. The cellular immunity was investigated in some patients with determination of the percentage of spontaneously-rosetting lymphocytes, of the DNCB skin-test reactivity before and after sensitization with DNCB and of skin-test reactivity to candida, trichophyton, varidase, OT and staphylo antigen. The functional efficiency of polymorphonuclear leucocytes was investigated by means of the NBT test and Staph. aureus, E. coli and Latex particles. All investigations were performed before, and 3, 6, 9 and 12 weeks after surgery. 4 methods only amongst the entire spectrum employed in the investigation proved to give sufficient evidence of signs of decreased efficiency of the immune response in the investigated patients: determination of tetanus antitoxin before and after immunization, a distinct increase in titre being observed only in 5 cases, determination of the sensitization to DNCB, which was positive only in 4 cases and determination of skin-test reactivity to varidase and OT, which was found to be less frequently positive than in controls. However, all these reactions showed no evidence of any correlation to surgical management and appeared merely to reflect characteristic responses of these cancer patients. Moreover, with the exception of the decrease in lymphocytes, no changes were detected in the data obtained by the other methods used in this study which might show some reflection of an alteration in response following surgery.

Antibodies, Neoplasm↗
PubMed1975

Demonstration of antibodies to collagen and of collagen-anticollagen immune complexes in rheumatoid arthritis synovial fluids.

Twenty-nine synovial fluids from patients with rheumatoid arthritis (RA) and 10 synovial fluids from patients with other joint diseases were investigated with regard to the presence of antibodies to denatured human collagen and of collagen-anticollagen immune complexes. 12 of the 29 RA synovial fluids showed anticollagen titres from 1:16 to 1:512 in passive haemagglutination. Only one patient in the group with no arthritis had a significant anticollagen titre of 1:32. Digestion of the synovial fluids with bacterial collagenase resulted in an anticollagen titre increase from two to four dilution steps in 9 of the RA fluids, while 6 previously negative RA synovial fluids showed anticollagen titres from 1:32 to 1:28 after digestion with collagenase. These results indicate the existence of collagen-anticollagen immune complexes in 15 of the 29 RA synovial fluids investigated.

Animals↗
PubMed1975

Biologic activity of soluble collagen-anticollagen immune complexes as demonstrated by passive cutaneous anaphylaxis.

Collagen-anticollagen immune complexes were prepared by gel filtration. Complex formation was chemically and serologically demonstrated. Complexes eluting in gammaM- and gammaG-peaks of antigen-antiserum mixture showed strong positive reactions in PCA experiments performed with 20 guinea pigs. Control preparations of gammaM- and gammaG-peaks of antiserum devoid of antigen gave significantly lower PCA-response. The positive reaction of control preparations can be explained in part by a certain degree of cross-reactivity of anticollagen-antibodies with guinea pig collagen.

Animals↗