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Biomedical subjects

J Kohn

Publications and source records attributed to J Kohn.

At least 73 records · Page 4Linked to original sources
PubMed1983

Antibody synthesis within the central nervous system: comparisons of CSF IgG indices and electrophoresis.

VARIOUS LABORATORIES HAVE REPORTED DIFFERING SUCCESS RATES IN THEIR ABILITY TO DETECT INTRATHECAL SYNTHESIS OF ANTIBODY WHEN COMPARING THE INDEX OF [FORMULA: see text] with electrophoretic analysis. We selected 44 patients in the borderline area of minimal and/or equivocal abnormality by IgG index. Electrophoretic analysis (on polyacrylamide gels for oligoclonal gamma globulin pattern) of parallel specimens was performed at the same time. The number of samples giving a normal index but showing oligoclonal bands varied between 34% and 43% depending on the cut-off point. The views about normal barrier functions underlying such indices are discussed with particular reference to the pathophysiology of the blood-CSF barrier.

Albumins↗
PubMed1982

Changes in serum amylase and its isoenzymes after whole body irradiation.

A study was carried out to assess the effect of total body irradiation on pancreatic and parotid isoenzymes of amylase in patients about to undergo bone-marrow transplantation who had received high-dose cyclophosphamide. Twelve patients were studied, enzyme activity being measured before and at various times after total body irradiation. Serum total amylase activity rose rapidly within 12 hours of irradiation to a maximum at 36 hours, returning to normal by six days; most of the increase was derived from salivary damage, with a much smaller pancreatic component. These results confirm that radiation produces acute changes in amylase activity, which may be of use in assessing radiation-induced damage.

Amylases↗
PubMed1982

Vitamin A and retinol-binding protein in patients with myelomatosis and cancer of epithelial origin.

Serum vitamin A and retinol-binding protein (RBP) concentrations were measured in patients comprising 53 myeloma and 28 epithelial cell cancer cases. Vitamin A levels in these patients were found to be significantly lower than those in the 30 healthy subjects, the effect being more marked in the patients with cancer of epithelial origin. The serum concentrations of retinol-binding protein (RBP) fell in parallel with vitamin A in the epithelial cancer patients, while the RBP concentrations remained unaffected in the patients with myeloma, suggesting that the underlying factor for resulting low vitamin A levels may be different in these two groups of patients.

Adult↗
PubMed1982

Serum concanavalin-A binding in rheumatoid arthritis.

A nephelometric assay of concanavalin-A binding of serum acute phase proteins (con-A binding) has been used in cross-sectional and sequential studies of disease activity in rheumatoid arthritis (RA). Con-A binding correlated well with blood viscosity, C-reactive protein, and other individual acute phase reactants in patients with active RA. Twenty-four patients were treated for 6 months with D-penicillamine and assessed clinically and seriologically. Clinical improvement was accompanied by significant falls in both C-reactive protein and con-A binding, although the serological changes did not always occur in parallel in individual patients. The advantages of this simple, cheap assay of acute phase proteins are discussed.

Adolescent↗
PubMed1980

The use of concanavalin A to measure acute phase proteins by laser nephelometry.

Concanavalin A (con A) binds specifically to alpha-D-glucosyl, alpha-D-mannosyl and sterically related structures. Many serum glycoproteins contain such residues and will therefore bind and precipitate con A. Using this principle, a nephelometric method was developed for measuring total con A binding proteins in serum. The effect of parameters such as con A to glycoprotein ratio, polymer enhancement, reaction time, stability of the complexes and potential inhibitory molecules such as glucose and calcium were assessed. A brief clinical evaluation of the assay in human sera showed that con A binding correlates well with specific acute phase protein-changes in inflammatory disease and may be used as an index of disease activity. Preliminary studies show that con A binding also reflects disease activity in a number of animal species and thus may provdie a much needed index of inflammation in the experimental animal and in veterinary practice, where species specific antisera to acute phase proteins are not widely available and protein analyses have been rather neglected. The assay is rapid, cheap and may be performed on automated nephelometric systems.

Adult↗
PubMed1980

The interpretation of marker protein assays: a critical appraisal in clinical studies and a xenograft model.

Although useful in the management of malignant testicular tumours, alphafoetoprotein and human chromonic gonadotrophin are not perfect parameters of tumour bulk. In a series of 65 patients with marker-positive advanced disease, 23 showed the phenomenon of discordance of markers or dissociation from tumour response. Transplantable human malignant teratoma xenografts were established in immune-suppressed mice as models of the human disease. In the model system, it was demonstrated that tumour AFP concentration was reflected by AFP titres in the blood, but that tumour AFP (or blood AFP) did not correlate well with tumour size. One xenograft line illustrated the evolution of marker-negative tumour cells from a patient who was initially AFP-positive.

Animals↗
PubMed1980

[The phenomenon of double line of IgG in immunoelectrophoresis (author's transl)].

Immunoelectrophoretic studies of patients' sera occasionally reveal a parallel splitting of the IgG precipitation line if the test is performed with polyvalent antihuman antiserum directed not only against the Fc-part of the IgG molecule. This phenomenon has been studied in a patient with discoid lupus erythematosus and another patient with lymphadenopathy of unknown origin. Apparently, this finding was not due to a monoclonal gammopathy: In the cellulose membrane electrophoresis no extragradient could be observed and assays with antisera directed against free and bound light chains showed a regular pattern. The splitting of the IgG precipitate is much rather caused by polyclonal IgG with a high proportion of slowly diffusing heterogenous IgG-x, as has been found in studies using the immunoelectrophoresis as well as the analytical ultracentrifuge. It was not due to Fab fragments.

Female↗