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Biomedical subjects

M Knedel

Publications and source records attributed to M Knedel.

At least 55 records · Page 3Linked to original sources
PubMed1977

[The use of primate tissue homogenates for quality control in the creatine kinase-MB determination with inhibiting antibodies (author's transl)].

The creatine kinase isoenzymes CK-MM, CK-MB and CK-BB from Rhesus monkey heart and brain tissue homogenates were separated chromatographically. Thereafter it could be demonstrated that the activity of the simian subunit CK-M is completely inhibited by anti-inhibitory-CK-M serum. Thus control sera from simian tissue are in principle suited for quality control in an immunological determination of creatine kinase-MB. The intra-assay variance and interassay variance were n = 56, -/x = 29.2 U/1, SD = 3.2 U/1, CV = 11.1% and n= 12, -/x = 166.7 U/1, SD = 5.0 U/1, CV = 3.0% respectively. It is desirable to develop control sera with catalytic concentrations of creatine kinase-MB in a lower range.

Animals↗
PubMed1976

[Determination of creatine kinase-MB in serum using inhibiting antibodies (author's transl)].

A new method for the determination of creatine kinase-MB activity in the serum is presented. The principle of this method is the direct measurement of the activity of creatine kinase M subunits by inhibiting antibodies. The total test procedure takes 15 min. In the sera of all the 83 patients tested, who have clinically proven myocard infarction, creatine kinase-MB activity can be measured between the 6th and 28th hour after infarction. At the time of maximum total creatine kinase activity the percentage of creatine kinase-MB activity is between 6 and 17%, the mean value being 8%. In cases of emergency this method can be used for the differential diagnosis of elevated total creatine kinase activities of unknown origin.

Clinical Enzyme Tests↗
PubMed1976

[Multiple myeloma with monoclonal IgE gammopathy (author's transl)].

In a 48-year-old female patient with monoclonal gammopathy and histologically proven plasmocytoma IgE could be demonstrated in bone marrow plasma cells by means of direct immunofluorescence. Immunoelectrophoresis showed a light-chain type chi. Radiographically diffuse osteolytic skeletal lesions were found. Bence-Jones proteinuria and plasma cell leukaemia were absent. This patient represents the fourth recognized case of IgE myeloma. The chi/lambda ratio in IgE myeloma is 1:1 according to present knowledge.

Bone Marrow↗
PubMed1976

Steroid phosphorus compounds. V--Mass spectrometry of phosphinic esters of monohydroxy steroids.

The mass spectra of the dimethylphosphinic, dimethylthiophosphinic and dimethylphosphinous ester derivatives of several monohydroxy steroids are reported. The fragmentations of the derivatized steroids largely depend on the nature of the phosphorus-containing ester group. Phenolic ester derivatives exhibit the base peak at the molecular ion, whereas the spectra of the secondary phosphinic esters are dominated by very intense protonated phosphinic acid ions [Me2P(XH)(OH)]+ at m/e 95 (X =O) or at m/e 111 (x = s). The present results also indicate the low ionization potential for the phosphinic ester group. Due to their good gas chromatographic properties, these steroid derivatives appear to be particularly suitable for gas chromatographic mass spectrometric analysis of biochemical materials.

Androsterone↗
PubMed1976

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.

Antigen-Antibody Reactions↗
PubMed1975

[Determination of creatine phosphokinase-MB in the serum of patients with myocardial infarction by an immunological method (author's transl)].

The immunological method of determining creatine phosphokinase-MB in the serum of patients with myocardial infarction described here is based on the differential measurements of CK-activities before and after a specific immuno-precipitation of the CK-MB type. The minimum activity of the CK-MB-type which it is possible to determine with this method is 4% of the total activity. In patients with clinically confirmed myocardial infarctions 1-15% (mean 7.8%) of the total activity can be calculated as CK-activity of the MB-type on the first/second day(s) after the infarction. In patients with increased total CK-activity and without verified infarction the CK-MB content does not differ significantly from zero. The differences between the two groups are statistically significant. In patients with myocardial reinfarction the CK-MB-activity is higher than that after the first infarction. The immunological method to determine creatine-phosphokinase isoenzyme MB is of differential-diagnostic value in myocardial infarction.

Clinical Enzyme Tests↗