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Biomedical subjects

C Steffen

Publications and source records attributed to C Steffen.

At least 91 records · Page 5Linked to original sources
PubMed1981

Human serum inhibitors of collagenase as revealed by preparative isoelectric focusing.

Single step separation of pooled normal human serum by means of preparative isoelectric focusing in the range from pH 3.5--9.8 revealed more heterogeneous inhibition of collagenolytic activity than previously reported. Essentially three inhibition zones were resolved. According to their electrophoretic behaviour the respective serum fractions displaying inhibitory activity were designated alpha-, beta- and gamma-collagenase inhibitors. The main component responsible for collagenase inhibition in the alpha-zone was found to be alpha 2-macroglobulin. In the beta-zone inhibitory activity focused around pH 6.3. In the gamma-range a non-dialysable cationic component focusing at pH 9.2 was also able to decrease collagenolytic activity derived from rheumatoid arthritis synovial culture supernatant. These findings were supported by single step separation of serum on DEAE-anion exchange chromatography.

Acetic Anhydrides↗
PubMed1981

Severe chlorate poisoning: report of a case.

A case of severe sodium chlorate poisoning was observed within 5 h after suicidal ingestion of 150-200 g of the herbicide. Methaemoglobinaemia was the early symptom of the intoxication. Treatment with methylene blue and ascorbic acid could not prevent a massive haemolysis with disseminated intravascular coagulation. Hypercoagulation and hyperfibrinolysis could be treated successfully with exchange transfusions, heparin and fresh plasma. During the first hours, 70 mmol chlorate were excreted before complete renal failure occurred which required haemodialysis for several weeks. Clinical observations and in vitro experiments provide evidence that methylene blue is effective only in the very early stages of chlorate poisoning. Consequently, the following treatment is suggested: gastric lavage, exchange transfusion, bicarbonate infusion, haemodialysis, anticoagulation with heparin and substitution of clotting factors if necessary.

Adult↗
PubMed1981

Concanavalin A-induced suppressor cell activity and in vitro immunoglobulin secretion in rheumatoid arthritis: correlation with clinical and immunological parameters.

Concanavalin A-induced suppressor cell activity was found moderately but significantly (P less than 0.05) decreased in RA patients treated with nonsteroidal antiinflammatory drugs (31 +/- 7% suppression) as compared to patients on remission-inducing drugs, such as gold, penicillamine, or chloroquine (51 +/- 6%) or to healthy individuals (50 +/- 6%). Also, lymphocytes from patients with antibodies to collagen mediated lower suppression (33 +/- 7%) than lymphocytes from patients without evidence for these autoantibodies (61 +/- 11%). No significant difference between patients and controls or between individual groups of patients were observed in regard to IgM and IgG secretion induced by pokeweed mitogen. Thus, although no indication for a severe derangement of regulatory cells in peripheral blood of RA patients could be observed in this study, a slight deficiency of ConA-inducible suppressor cells that may be reverted by remission-inducing drugs seems to be present in RA.

Adult↗
PubMed1981

Clinical and histopathologic correlation of midge bites.

Many species of files viciously bite humans and animals. I had the opportunity to observe such bites by the gnat Leptoconops torrens during a recent epidemic that occurred in an inland desert area of California. The bite may produce an urticarial wheal, but, more characteristically, it induces formation of a hard, indolent, pruritic papule. In biopsy specimens taken within three days after the bite, the superficial infiltrate was composed or lymphocytes and histiocytes, while eosinophils were the preponderant cell found in the deeper dermis and subcutaneous fat. These clinical and histopathologic findings are similar to those reported for the bite of the blackfly, Simulium.

Diptera↗
PubMed1980

Lymphocyte transformation to denatured type I collagen and B lymphocyte alloantigens in rheumatoid arthritis.

Peripheral blood lymphocytes transformed significantly to denatured type I collagen in 22 of 38 patients with rheumatoid arthritis (58%), 1 of 9 patients with Reiter's disease (P less than 0.05), and 9 of 32 controls (28%) (P less than 0.01). Determination of HLA antigens revealed significant differences between 24 rheumatoid arthritis (RA) patients and a control population for HLA-DRw4 (75% versus 23%). No correlation was observed between lymphocyte transformation to collagen and antibodies to collagen, rheumatoid factor, stage or duration of RA, or HLA antigens.

Adult↗
PubMed1980

Lack of in vivo lipid peroxidation in experimental paraquat poisoning.

Ethane evolution was measured in rats breathing pure oxygen. Animals injected i.p. with a lethal dose of paraquat (50 mg/kg) developed signs of pulmonary insufficiency within 3 hours and died within 24 hours. Ethane evolution, a parameter of lipid peroxidation in vivo, was increased over control levels only by 26% after 4 hours. It is concluded that this increase is too small to support the theory that lipid peroxidation is the biochemical mechanism of paraquat toxicity.

Animals↗
PubMed1980

Demonstration of antibodies to denatured type I and type II collagen in juvenile rheumatoid arthritis, Still's syndrome and controls by [14C] collagen radioimmunoassay.

From 88 sera of patients with juvenile rheumatoid arthritis 30.6% showed antibodies to denatured type I collagen an 31.8% antibodies to type II collagen, a percentage which corresponds to radioimmunoassay results in adult RA. Rheumatoid factors were demonstrated with Waaler-Rose test in 14.7% and with latex test in 6.8% of investigated patients. Results of investigations with collagen types I and II correlated in 73.7%. Whilst type I collagen antibodies were found with equal frequency in active and non-active stages, type II antibodies were twice as frequent in active stages as in non-active stages. Sixteen sera of children with non-rheumatoid diseases had no collagen antibodies. JRA sera and controls differed with statistical significance in regard to collagen antibodies. 36 sera of children with Still's syndrome showed antibodies to type I collagen in 13.8% and antibodies to type II collagen in 33.3%. Both types of antibodies appeared more frequently in clinically active stages. The sera differed from controls with statistical significance in regard to collagen antibodies.

Adolescent↗
PubMed1980

Experimental arthritis induced by granulocyte collagenase.

Purified human granulocyte collagenase (1 mg %, 10 mg % or 50 mg %) was injected into rabbit knee joints (three groups of 6 animals each) three times within one week. Synovium and synovial fluid were investigated 18 hours, 1 week and 3 weeks after the last injection. After 18 hours, synovial fluids showed distinct cellular exudation, its size depending on the amount of collagenase applied. A smaller number of cells was seen after one week, while normal cell counts were observed 3 weeks after the last injection. Histologically, synovium showed an acute arthritis after 18 hours, whereas after 1 and 3 weeks a chronic proliferative form of arthritis with predominant activation of fibroblasts was diagnosed. As compared with an experimental arthritis induced with rheumatoid synovial collagenase, granulocyte collagenase was less arthritogenic. Neither trypsin nor saline injections induced distinct cellular exudation into synovial fluids nor histologic signs of arthritis.

Animals↗
PubMed1980

Suppressor cell activity in patients with rheumatoid arthritis.

Twenty-one patients with definite or classical rheumatoid arthritis (RA) were investigated for their suppressor cell activity by a Concanavalin A suppressor cell assay. Two patients had active disease, 9 moderately active disease, and 10 inactive disease according to clinical and laboratory parameters. A mean of 41 +/- 7% suppression was observed in RA patients as compared to 63 +/- 7% suppression observed in 10 healthy age and sex matched controls. No significant difference was observed between patients with moderately active or active disease (39 +/- 9%) and patients with inactive RA (43 +/- 10%). However, a borderline statistical significance (p = 0.05) was seen between controls and patients with moderately active or active RA. Use of autologous serum instead of AB serum for suppressor cell induction had no significant effect, although an increase of the mean suppression was noted (58 +/- 6%) in patient's group. No correlations existed between suppressor cell activity and presence of circulating Clq-binding immune complexes (solid-phase Clq assay), rheumatoid factor (Waaler-Rose test) or antinuclear antibodies (indirect immunofluorescence). This study indicates that lymphocytes of patients with inactive RA exert normal suppressor cell activity. It may well be that patients with active rheumatoid arthritis have decreased suppressor cell function. This will be assessed in a larger group of patients with active disease.

Adult↗
PubMed1980

Continuous and discontinuous ionography of the pancreatic juice and the parotid saliva using carrier-membrane disc-electrodes.

The methodology for continuous ionography (monitoring of electrolytic composition) of the pancreatic secretion using a multianalyser is described. The system employs special electrodes which make use of sensing elements constructed of carrier-membrane discs. The procedure has been applied successfully in investigations on animals and is presently being tested in the clinical diagnostic laboratory. The apparatus can also be used for discontinuous measurements, in which case it has the advantage of needing only extremely small quantities of fluid which can be analyzed successively for the different ions, as the electrodes are connected in series.

Calcium↗
PubMed1980

Spontaneous disappearance of molluscum contagiosum. Report of a case.

We report herein a case of molluscum contagiosum that healed spontaneously. The molluscum papules did not involute simultaneously, but became inflamed and disappeared individually over a period of months. Biopsy specimens were taken at various stages of inflammation and regression. The histopathology was consistent with a cell-mediated rejection reaction.

Humans↗
PubMed1980

Autoantibodies to collagen in patients with chronic liver diseases.

Sera of patients with various liver diseases were investigated for the presence of autoantibodies to type I collagen with a sensitive radioimmunoassay employing 3H-labelled collagen type I. A high percentage (69%) of patients with chronic liver diseases, equally distributed between chronic active hepatitis and alcoholic liver disease, was found to possess antibodies to denatured type I collagen, while no antibodies against native collagen were found. These antibodies belonged predominantly to the IgA immunoglobulin class. None of the patients with acute hepatitis or cholestatic liver disease, nor the healthy individual investigated had IgA-anticollagen antibodies. These findings may be useful as a parameter for the detection of chronic liver disease.

Acute Disease↗
PubMed1979

Absorption of paraquat by rat gut in vitro. Regional differences.

The absorption of radioactively labeled paraquat was measured in rat ileum, jejunum and colon by a micro everted sac technique (Semenza and Muhlhaupt, 1969). The absorption rate increased linearly over the range of concentrations measured (10(-5) to 10(-2) M) and was enhanced by nearly 50% in the absence of sodium ions. The absorption rate decreased in the order: ileum, jejunum, colon whereby in the colon still 65% of the values of the small intestine were observed.

Animals↗
PubMed1979

Collagen types and anticollagen-antibodies in Dupuytren's disease.

The relative proportion of collagen type I and type III in the aponeurosis of twenty-four patients with Dupuytren's disease was determined and compared with the aponeurosis of normal persons. The presence of considerable amounts of type III collagen was found in the Dupuytren's disease patients. The sera of the patients were screened for circulating anti-collagen antibodies using a sensitive radioimmunoassay. In seven out of the twenty-four patients low concentrations of these antibodies were found.

Adult↗
PubMed1979

[Clinical relevance of circulating immune complexes in patients with systemic lupus erythematosus and chronic polyarthritis].

Using a solid phase C1q assay, circulating immune complexes (IC) were detected in 15 of 55 patients with rheumatoid arthritis (RA) and 6 of 14 patients with systemic lupus erythematosus (SLE). In contrast to RA, presence of IC correlated to clinical disease activity in SLE patients. Preliminary short term follow up studies revealed additional differences between RA and SLE: whereas persistence of IC was noted in the patients with SLE, rapid changes of IC levels were observed in RA.

Arthritis, Rheumatoid↗
PubMed1979

[Intestinal resorption with 3H labeled enzyme mixture (wobenzyme)].

0.2 g of an enzyme mixture (Wobenzym) labelled with 3H-acetic anhydride, were given orally to guinea pigs, which were arranged in 4 groups of 5 animals. The animals of each group were sacrificed at intervals of 30 minutes, 2, 4 and 24 hours after application. Radioactivity of the small and large intestine, plasma, urine, liver, heart, kidney, and skeletal muscle were determined. It could be shown that the labelled mixture of enzymes was absorbed from the intestine and was demonstrable in significant amounts in plasma, urine, heart, kidney, liver and skeletal muscle.

Animals↗